Regarding a rear bag, I offer this for your consideration. I won’t claim that it’s the best possible method, but in addition to working pretty well for me, it’s very compact and easy to transport and keep handy. (I have never seen anyone else use it.) I was never very happy with the idea of trying to tote around a large, heavy bag to use in field positions.







The method relies on two elements: a rear monopod that’s attached to the stock and a small, firm “wedge” or triangle bag. As pictured I fold the monopod forward about 45 degrees, rest it on the bag, and then grasp the monopod, and sometimes along with the bag as well.

The bag pictured is by Triad Tactical, but I also have a slightly larger (and somewhat less expensive, IIRC) bag by the Champion brand; I’ve also seen a wedge bag made by another company, but don’t recall the name. The Triad Tactical bag is small enough to carry in a cargo pocket.

The monopod in this case is actually B&T Industries folding foregrip that can be locked in the 45° position. For a long time I used the Accu-Shot monopods, but the folding foregrip works much better for me for a couple of reasons. The item is of course expensive and it’s necessary to figure a way to mount a Picatinny rail section on the stock to attach it to, but I’ve done that with all my precision and semiprecision rifles. I have several of the B&T grips, but they’re easy to move from one rifle to another.

https://shop.accu-shot.com/sho...ar-furnishings/bt27/

Triad Tactical offers two sizes. The large I have never had much use for; the small is pictured above.
https://triadtactical.com/triad-tapered-rear-bag/

It looks like Midway also offers a very inexpensive tapered bag:
https://www.midwayusa.com/prod...015177023?pid=666600

The bag I use is homemade. It's as good a copy of this that I could create, with the materials I had on hand, and a ziploc full of rice as filler.

https://www.crosstac.com/shop-...al-rear-squeeze-bag/

I use it under a LMT SOPMOD stock.

Adopting your setup wouldn't fit my use-case for the rifle. As always, I appreciate your feedback and suggestions. Thank you.

So, I don't know how this conversation hadn't happened sooner: I was discussing my woes with my benchrest friend, and he's talking about how my expectations might be unreasonable. I ask him if he experiences POI shifts in his groups; group to group, day to day. He says yes. I say WTF. I've been sharing this struggle of mine with you for the past month, and you neglected to tell me the same exact thing happens to you? He says yeah; an inch or so at 100y is not uncommon. This guy shoots guns that are more accurate than mine, from conditions with less variables than mine, with ammo that is better catered than mine, and still experiences the group POI phenomenon. Am I a friggen crazy person? Surely fritz and sigfreund can pick up a rifle of theirs, and print a tidy group exactly where they want it to be on a given day, because that's where their rifle put it last time. Hell, fritz has said as much. My friend is not an idiot; he's not so much into the semi-auto practical/tactical side of things, but he's been shooting for a long time, and is no stranger to precision shooting.

He implied that my whole system has too many variables (something I have conceded and am trying to mitigate). Not just the "system", but a semi-auto in general. Am I going to keep chasin my tail because my gun just isn't up to snuff? He seems to think the AR in general has too many inherent variables. I don't want to chase my damn tail.

quote:

Originally posted by KSGM:
I was discussing my woes with my benchrest friend, and he's talking about how my expectations might be unreasonable. I ask him if he experiences POI shifts in his groups; group to group, day to day. He says yes.
He says yeah; an inch or so at 100y is not uncommon.

He implied that my whole system has too many variables (something I have conceded and am trying to mitigate). Not just the "system", but a semi-auto in general.
He seems to think the AR in general has too many inherent variables.

I haven't shot from a bench in a few years. I've never shot bench rest competition.

But I've met a few guys who did shoot bench, and I've seen a fair amount of webz reports. When shooting for groups, the good guys have 5-round groups at 100 yards that repeatedly measure .20" to .25". On a great day they will get under .15" spread, maybe even close to .1". Some of them shoot with quite heavy rifles, with really burly front & rear supports. They generally shoot uber-accurate chamberings, often based on a 6BR case. Many shoot free recoil -- meaning only their trigger finger touches any part of the rifle. A trigger with a pull weight that is measured in ounces, or maybe even tenths of ounces. The good shooters are the epitome of repeatability, regardless of whether they're shooting for group size or score. What has been leaned/developed/tweaked by bench rest shooters has flowed into F-Class, tactical, & ELR competition and made all disciplines more accurate.

I find it very odd that a bench rest shooter would see 1 MOA shifts in POI from one day to another. Unfathomable at the upper levels of competition.

All the instructors I've trained with at Rifles Only exhibit ridiculously consistent accuracy with their rifles. Tactical rifles, often 308 Win, folding bipods, from prone, from barriers, with rear bag support. Their 100-yard zeros don't change -- meaning no POI shifts. As my shooting fundamentals improved, as my rear bag use improved, as I reduced cheek weld pressure on the stock -- my POI shifts went away. I've had entire seasons of competition & training where I never touched my zero on both the 6.5CM and 308 Win bolt actions. Thousands of rounds. Traveling to matches in Wyoming, New Mexico, Nebraska, Colorado -- while training in Texas & Colorado. IIRC, on 6.5CM barrel #2, I never re-zeroed the scope after barrel break in -- all the way until the barrel went tits up. After initial zeroing, I doubt I've changed the POI on 6.5CM barrel #3, 6CM, 223 Remy, and 22lr bolt actions. Same with my 6.5CM and 6CM AR10s. Now that I've ditched that funky Magpul UBR stock for CTR and PRS stocks, I don't see POI shifts on any of my AR15s, either. I do confirm my 100-yard zero before matches, but I just don't see it changing from a mechanical rifle/ammo/optics standpoint -- unless a screw/bolt breaks or comes loose in my scope mount. And yes, back in the day before I had torque wrenches, the mount for 6.5CM barrel #1 became loose in the warmup for a match. I also experienced a receiver rail screw shear off on my 308 Win.

The only time I've seen POI shifts in recent years (meaning that I'm not dead-on my 100 yard zero), is when my shooting fundamentals are out of whack. This occurs more often than I like to admit, especially in the first shots of the day while training. After a bit a cursing, some self-reflection, a review of the fundamentals, and some dry firing -- voila, the zero/POI returns to where it should be. Isn't...that...amazing! I suspect that operating a chainsaw for a few hours prior to rifle practice isn't the best shooting warmup activity.

Semi-autos have a whole lot more shit going on during the firing process. The triggers aren't as good, there are reciprocating metal parts, there's gas going in multiple directions. I submit that many folks can learn to accurately shoot a 308 bolt action faster than they can with a 223 AR15. The fundamental have to be rock solid to shoot semi-autos with great accuracy. But ARs can be very accurate.

One of Sniper's Hide better training videos. From way back, with Jacob Bynum of Rifles Only on the gun. Here's an illustration of how POI can shift.

Jacob's the real deal with a rifle. He kicked ass in competitions, before PRS was a thing. He's probably trained more agency, sniper, SWAT, contractor, and weekend warrior competitors than just about anyone.

positions -- shooting fundamentals

Thanks for the continued feedback, fritz. I almost wanted to tell my buddy I thought he was off the mark, but he's my friend, and I wasn't sure I was right.

Anyway, I'll press onward, paying strict attention to my fundamentals. You have shared that video previously, in another thread. I re-checked my parallax today, and actually made a small adjustment. I'll update more soon, I hope.

quote:

Originally posted by fritz:
Now that I've ditched that funky Magpul UBR stock for CTR and PRS stocks, I don't see POI shifts on any of my AR15s, either.

You just piqued my interest. To what do you attribute POI issues from the UBR stock? I ask as the owner of several.

quote:

Originally posted by IndianaBoy:
To what do you attribute POI issues from the UBR stock?

The interaction of my facial structure, my preferred cheek weld to obtain a sight picture in the center of my optics, and the height above bore for my optics. The UBR just didn't work right for me, regardless of how much I tried.

I made a mistake on stock types -- I use the STR now for my collapsible-stock lowers, not the CTR.

I bought a UBR because the webz reviews were stellar. Great cheek welds, a nice transition for those who use PRS stocks for the heavier precision builds. From the beginning, I didn't like the way the UBR extends & contracts. One portion of my face was always hanging in mid-air, regardless of where I placed scopes on the receivers. In order to put my eye in the center of the scopes' eyeboxes, I had to squish my face down on the UBR stock -- more so than any of my other stocks and rifles. The additional downward pressure on the UBR stock tended to send rounds high. I was generally OK with solid prone positions, but transitions to barrier positions many times resulted in higher than expected impacts.

I discussed this with one of the region's better shooters during a multi-gun match. We were in the same squad during the 2-day match and we carpooled to the match. When convenient, he watched my shooting. We had some pretty frank discussions about technique & equipment. During the subsequent weeks I made changes to stocks, optics heights, and cheek weld practices. Paired with rear bag adjustments, my high POI issues pretty much stopped right then and there. I was fortunate to be around talented shooters.

I've been around long enough and participated in enough sports to know that many folks want to blame their performance issues on equipment. I respect Magpul products and just didn't want to place blame on the UBR. But in my case the human-to-equipment interface didn't work right with a UBR stock.

IMO, this is one of the rare instances where equipment -- not technique -- was the primary cause of accuracy issues.

quote:

Originally posted by fritz:

quote:

Originally posted by IndianaBoy:
To what do you attribute POI issues from the UBR stock?

The interaction of my facial structure, my preferred cheek weld to obtain a sight picture in the center of my optics, and the height above bore for my optics. The UBR just didn't work right for me, regardless of how much I tried.

I made a mistake on stock types -- I use the STR now for my collapsible-stock lowers, not the CTR.

I bought a UBR because the webz reviews were stellar. Great cheek welds, a nice transition for those who use PRS stocks for the heavier precision builds. From the beginning, I didn't like the way the UBR extends & contracts. One portion of my face was always hanging in mid-air, regardless of where I placed scopes on the receivers. In order to put my eye in the center of the scopes' eyeboxes, I had to squish my face down on the UBR stock -- more so than any of my other stocks and rifles. The additional downward pressure on the UBR stock tended to send rounds high. I was generally OK with solid prone positions, but transitions to barrier positions many times resulted in higher than expected impacts.

I discussed this with one of the region's better shooters during a multi-gun match. We were in the same squad during the 2-day match and we carpooled to the match. When convenient, he watched my shooting. We had some pretty frank discussions about technique & equipment. During the subsequent weeks I made changes to stocks, optics heights, and cheek weld practices. Paired with rear bag adjustments, my high POI issues pretty much stopped right then and there. I was fortunate to be around talented shooters.

I've been around long enough and participated in enough sports to know that many folks want to blame their performance issues on equipment. I respect Magpul products and just didn't want to place blame on the UBR. But in my case the human-to-equipment interface didn't work right with a UBR stock.

IMO, this is one of the rare instances where equipment -- not technique -- was the primary cause of accuracy issues.

Excellent analysis, thank you for sharing. Something for me to keep in mind. Especially the part about not putting a lot of cheek weld pressure on the stock. I had never considered that.

Another question for you Fritz. Do you find any measurable POI shifts with a gas gun comparatively between pushing your shoulder straight forward into the stock with some pressure vs very light/minimal pressure?

Same question of a hand resting on top of the handguard or on top of the scope with the rifle on bags such as seated behind a barricade type prop. Or is it better to place the hand elsewhere and not influence the way the rifle moves.

If you get all the other fundamentals correct, will a rifle shot with the free recoil technique have a different POI than a rifle with some shoulder pressure?

None of my AR triggers are light enough to truly shoot free recoil, but I am wanting to experiment with more or less physical control of the gun, and would rather start from a position of experience from someone who knows than burn a lot of ammo testing it myself.

quote:

Originally posted by fritz:
The additional downward pressure on the UBR stock tended to send rounds high.

After first reading the suggestion about minimum stock (cheek) weld pressure, I’ve been trying to keep it in mind, especially in the prone position, and I believe it’s made a significant difference for me. I shot a drill today at 130 yards with two shots from the prone position and two from kneeling supported by a tripod. Although four shots isn’t much, they all clustered around the same POI.

quote:

Originally posted by IndianaBoy:
Another question for you Fritz. Do you find any measurable POI shifts with a gas gun comparatively between pushing your shoulder straight forward into the stock with some pressure vs very light/minimal pressure?

Same question of a hand resting on top of the handguard or on top of the scope with the rifle on bags such as seated behind a barricade type prop. Or is it better to place the hand elsewhere and not influence the way the rifle moves.

If you get all the other fundamentals correct, will a rifle shot with the free recoil technique have a different POI than a rifle with some shoulder pressure?

IMO if everything else in the shooting is done correctly, the POI is the same with zero, minimal, or heavy rear pressure on the buttstock -- as long as the pressure is exactly on the bore axis. With minimal or no pressure on the buttstock, the rifle will recoil more, and the recoil must be allowed to move straight back on the bore axis.

The most consistent method for me is a fair amount of forward pressure, with noticeable bipod loading. I'll shoot an AR15 with equal or greater buttstock pressure as a 308 bolt action, even though the 308's recoil is 4-5 times that of a 223. If possible, I'll load the bipod harder with an AR than with a bolt action.

I will shoot an AR or bolt action with free recoil, if necessary, from a barricade. A vertical pallet supported by T-posts is a good example. A common method for this is placing the rifle's balance point on a bag on top of the pallet. Then my left hand is on top of the scope turret, pressing straight down. If the pallet is really wobbly, my shoulder may not even touch the buttstock.

I prefer not shooting like this, because the rifle jumps enough to make spotting impacts really tough. Believe me, a 308 rifle on a wobbly pallet with no shoulder support jumps....just a bit. But POI doesn't change if the rest of my setup and technique is good. Shooting free recoil with my ARs does present more issues with trigger control than with my bolt actions. I believe my bolt action triggers are in the 2 to 2.5 pound ballpark, whereas my ARs are in the 4 to 4.5 pound ballpark. I try to compensate for this a bit by squeezing the AR trigger between my index finger and the web of my hand. Bolt actions are more of a straight back press with the index finger. Also, trigger travel with a bolt action is shorter & crisper, and the lockup time is less.

quote:

Originally posted by fritz:

quote:

Originally posted by IndianaBoy:
Another question for you Fritz. Do you find any measurable POI shifts with a gas gun comparatively between pushing your shoulder straight forward into the stock with some pressure vs very light/minimal pressure?

Same question of a hand resting on top of the handguard or on top of the scope with the rifle on bags such as seated behind a barricade type prop. Or is it better to place the hand elsewhere and not influence the way the rifle moves.

If you get all the other fundamentals correct, will a rifle shot with the free recoil technique have a different POI than a rifle with some shoulder pressure?

IMO if everything else in the shooting is done correctly, the POI is the same with zero, minimal, or heavy rear pressure on the buttstock -- as long as the pressure is exactly on the bore axis. With minimal or no pressure on the buttstock, the rifle will recoil more, and the recoil must be allowed to move straight back on the bore axis.

The most consistent method for me is a fair amount of forward pressure, with noticeable bipod loading. I'll shoot an AR15 with equal or greater buttstock pressure as a 308 bolt action, even though the 308's recoil is 4-5 times that of a 223. If possible, I'll load the bipod harder with an AR than with a bolt action.

I will shoot an AR or bolt action with free recoil, if necessary, from a barricade. A vertical pallet supported by T-posts is a good example. A common method for this is placing the rifle's balance point on a bag on top of the pallet. Then my left hand is on top of the scope turret, pressing straight down. If the pallet is really wobbly, my shoulder may not even touch the buttstock.

I prefer not shooting like this, because the rifle jumps enough to make spotting impacts really tough. Believe me, a 308 rifle on a wobbly pallet with no shoulder support jumps....just a bit. But POI doesn't change if the rest of my setup and technique is good. Shooting free recoil with my ARs does present more issues with trigger control than with my bolt actions. I believe my bolt action triggers are in the 2 to 2.5 pound ballpark, whereas my ARs are in the 4 to 4.5 pound ballpark. I try to compensate for this a bit by squeezing the AR trigger between my index finger and the web of my hand. Bolt actions are more of a straight back press with the index finger. Also, trigger travel with a bolt action is shorter & crisper, and the lockup time is less.

Thank you very much for the info. Extremely helpful.

So, I got fed up with the persistent shifts. I felt like I was throwing ammo in the friggen trash. So, in an effort to eliminate more variables, I removed the ADM/Leupold combo, and installed an Elcan Specter. So far so good...

Three five-shot strings over three days. No POI shift. Not even first shot elevation deviation I had experienced before. I am confident that my Leupold/ADM setup was doing me wrong, as I never could get this degree of consistency out of it. I am glad that my fundamentals aren't as jacked-up as I was beginning to suspect. I am going to send the Leupold in for service.

I think I may be getting some real, usable feedback now, which is refreshing. I do have a first shot POI deviation, relative to the remaining impacts; but it is slightly to the right, not absurdly high.

The short version is I am going to use my Elcan while I pinch pennies for another higher magnification scope, in a Spuhr mount.

Shooting was conducted at 100M, off a Harris bipod and rear squeeze bag, using the 4x Elcan, shooting 73gr FTX. The targets are not 1" squares, because the Elcan's center dot is too big for that to be repeatable. The inside of the tape box is about 3" squared, and I center the Elcan's dot in the box.

https://photos.app.goo.gl/2fVMT5JpvM68jtga7

quote:

Originally posted by KSGM:
...while I pinch pennies for another higher magnification scope, in a Spuhr mount.

I don't get the special appeal of Spuhr mounts. Sure, they look beefy and cool. The company makes all sorts of claims of reliability. And yes, I know competitors who have - and still use - Spuhr mounts.

I have Nightforce ($260), JP ($300), GG&G ($200), Warne ($150), and LaRue one-piece mounts on AR10s and AR15s. They all work, but I like the NF mounts the best. My rifles have survived rough handling in multi-gun matches, travel via car & plane, being dropped off the back of UTVs & pickups while bouncing across the pastures. They all hold zeros.

I know competitors who have Seekins ($300), Badger ($300), Leupold ($250), Vortex ($150), and Burris ($150) mounts. All of these mounts work for the competitors. They hold zero, the owners don't baby their rifles, the rifles get bumped in competition, the rifles get jostled around when travelling to matches.

The real test of how rings/mounts hold up is by rough use and extended travel. I know of some who swear by Spuhr mounts, when their most challenging movement is the 50 feet from the back of the SUV to the concrete shooting bench -- not much of a test IMO.

Maybe a Spuhr mount is more solid than my fleet of mounts. Maybe even my NF mounts. But my NF mounts (and the others) maintain zeros to a 1/4 MOA or less over years of use. Good enough for me.

The goal is still RTZ performance, after removal and reinstallation. I would of course use any of the myriad other options, if I was not still vying for that ill-advised performance aspect. Spuhr seems to be potentially better in this regard, based on the limited anecdotal evidence available. I have considered the Nightforce as well, as I actually don't want a QD mount; I intend to utilize torque limiter bits instead.

*The Nightforce torque tool kit makes up the difference in price anyway. I know there's other ways to make this happen, but I am leery of cheaper torque wrenches, when the goal is repeatability and consistency.

Spuhr mount $410
Torque kit $120

NF mount $260
Torque kit $275

This would be different if I could be assured that 65 in/lbs is adequate for the NF mount. They say 68, and that's what their kit enables. There are plenty of kits with 65 torque tools, for less money, as that is a common spec among most other mount makers.

This message has been edited. Last edited by: KSGM,