SIGforum
Anyone Here Reload for a SIG PE/Stgw 57?

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/840601935/m/9610009164

October 10, 2019, 02:05 PM
MG34_Dan
Anyone Here Reload for a SIG PE/Stgw 57?
I'm cross posting this on a few boards hoping to find a knowledgeable individual.

It seems that all the info I have seen for 7.5 Swiss ammo is for a K31. Does anyone here reload 7.5x55 for a SIG PE57? I ran into an issue with my reloads in a PE57. I followed the load recommendations and cartridge overall length specifications (3.04" - 3.06") as published in various reloading manuals. The problem I'm having has to do with using Hornady 168gr HPBT match bullets. My loaded ammo is too long to chamber in my PE57. What is the correct OAL when using these bullets?


“Elections have consequences, and at the end of the day, I won.”
– Barack Hussein Obama, January 23, 2009
October 10, 2019, 03:01 PM
sourdough44
I would investigate a method to measure where any particular bullet touches the ‘lands’ at what COL. Once that length is known, you can look at book & magazine COL limits, adjust as needed.

I have seen two guns made by the same Co(Savage 110 30-06) have different(slightly) COL max lengths. So even if someone offered a measurement, there may be slight differences from your gun.

Without a tool, you could experiment, Black marker, various lengths, & see where you touch. That’s the ‘shade tree’ method. One danger with loads to long is a bullet stuck in the bore as you unload a long round.
October 10, 2019, 07:36 PM
MG34_Dan
quote:
Originally posted by sourdough44:
I would investigate a method to measure where any particular bullet touches the ‘lands’ at what COL. Once that length is known, you can look at book & magazine COL limits, adjust as needed.

I have seen two guns made by the same Co(Savage 110 30-06) have different(slightly) COL max lengths. So even if someone offered a measurement, there may be slight differences from your gun.
Without a tool, you could experiment, Black marker, various lengths, & see where you touch. That’s the ‘shade tree’ method. One danger with loads to long is a bullet stuck in the bore as you unload a long round.

Here are some pictures for clarification:

Reload round on left, GP11 on right (both have same cartridge overall length)


Bullet ogive comparison, reload on left, GP11 on right


Reload striking chamber throat


Non-verified seating depth for Hornady 168gr HPBT (seems quite deep to me)



“Elections have consequences, and at the end of the day, I won.”
– Barack Hussein Obama, January 23, 2009
October 10, 2019, 10:27 PM
Watergoat
Hornady seems to design their bullets with full diameter carried farther forward than some other brands, then a sharper nose angle. I have had your problem with several calibers. Try the same OAL using Sierra, or Nosler bullets, I think that will fix the problem.
October 11, 2019, 03:53 AM
sourdough44
Yes, that bullet on the left reaches full size closer to the tip, obviously.

That’s the reason it’s fairly common practice to measure to stay a tad off the lands.