375 Snipetac Case Length

[JerryLee]

Just joined the forum so please be patient with me.

I just acquired a 375 Snipetac (Stiller action, 1:8 32" Bartlein) that's having some pressure issues and am trying to constrain all the variables. The original owner says the shoulder on the reamer measures 3.084" so I assume my brass should be slightly shallower than this measurement. The fire formed cases (max 3-4 times fired) are measuring between 3.030" and on the outside 3.056" from what I'm seeing but some are still closing hard in the chamber. He had been neck sizing exclusively after annealing each time he reloaded.

The loads are 138 grains of R50 with a 400 grain Badlands SICBM and are right at 3010 with very little standard deviation. Very accurate but any time there's any tightness on the bolt closing guaranteed that the case will stick and chances are the extractor will fail to pull the case out.

The pressure issues are causing the extractor to fail (Stiller action) and sometimes break. I've got the latest and greatest extractor from PT&G and it won't work on a stuck case. Unfortunately I think it has to do with the excessive length of the extractor and the size of the spring (AR15 extractor spring) used on it.

I intend to try Badlands 350 and 376 grain SICBMs but want to see if anyone knows of a standard case length for the Snipetac first.

Any thoughts?

 

[Quickshot]

I’m running ing the same rig. I use the go-gauge to set back the shoulder. I use a shoulder datum reference attached to a caliper. Measuring the case length only tells you when to trim the cases. Maybe these photos will help

 

[Geno C.]

Have Adam get the print from Ptg or you can. That’ll give the the chamber lengths d therefor the max case length

 

[JerryLee]

I’m running ing the same rig. I use the go-gauge to set back the shoulder. I use a shoulder datum reference attached to a caliper. Measuring the case length only tells you when to trim the cases. Maybe these photos will help
View attachment 7156867View attachment 7156868

I’m running ing the same rig. I use the go-gauge to set back the shoulder. I use a shoulder datum reference attached to a caliper. Measuring the case length only tells you when to trim the cases. Maybe these photos will help
View attachment 7156867View attachment 7156868

This certainly helps! I have a call into PT&G to get the "GO" gauge so I can do exactly what you're doing here. One question for you though and this is very similar to what the reamer specs out to for my chamber, what would you trim your cases to? I'm thinking 3.030" to allow 0.010" of clearance. Thanks!

 

[JerryLee]

Have Adam get the print from Ptg or you can. That’ll give the the chamber lengths d therefor the max case length

Have Adam get the print from Ptg or you can. That’ll give the the chamber lengths d therefor the max case length

Will do. He measured the reamer based on the drawing above for me last night. Thanks!

 

[Quickshot]

One question for you though and this is very similar to what the reamer specs out to for my chamber, what would you trim your cases to? I'm thinking 3.030" to allow 0.010" of clearance. Thanks!

My trim to case length is 3.030”. That gives 13 thousandths of clearance in my chamber. I use a Giraud trimmer as part of my brass prep. The 35deg shoulder doesn’t have much case growth.
Cheers,

 

[JerryLee]

My trim to case length is 3.030”. That gives 13 thousandths of clearance in my chamber. I use a Giraud trimmer as part of my brass prep. The 35deg shoulder doesn’t have much case growth.
Cheers,

I found what looks like a decent case trimmer at C4HD. It will do 50BMG and down. Almost $500 though. They've been my go to on a lot of things since I got started loading as with the 375 I now have 1.25" dies but my Hornady press is 1.5" and had to have an adapter. They had it but no one else could come up with it. It was in their inventory. Great guys too so they seem thus far. Any thoughts on their trimmer? It looks like the Giraud trimmer would be at least that much and about another $150 or so per additional caliber.

 

[ZiaHunter]

Running a Stiller TAC 408 with a Bartlein 36" 1:7 chambered in the SnipeTac. Dies setup to set the shoulder back .002-.003 with no issues. I have a Giraud Trimmer and had to have a blank reamed for the shell holder since they did not make one for the SnipeTac. Anneal and FL size after firing. Have several NS dies on my shelf and never use them anymore and only FL size. If you necks are too long it can definitely create pressure issues. If you can remove the ejector on the bolt you can check you sizing using the Wheeler method. I use it on most of my rifles to check die setup.

 

[ELR researcher]

I found what looks like a decent case trimmer at C4HD. It will do 50BMG and down. Almost $500 though. They've been my go to on a lot of things since I got started loading as with the 375 I now have 1.25" dies but my Hornady press is 1.5" and had to have an adapter. They had it but no one else could come up with it. It was in their inventory. Great guys too so they seem thus far. Any thoughts on their trimmer? It looks like the Giraud trimmer would be at least that much and about another $150 or so per additional caliber.

Thanks for the heads-up on the CH4D trimmer, new to me, though I suspect it has been around for a very long time.

Personally, I've found the Wilson trimmers are an excellent solution (https://lewilson.com/case-prep-tools/case-trimmers/). While their base units are not powered, they can be powered with one of their trimmer power adapters (drill motor power). Their center-support/case holder system is, IMO, the best available to get the alignment needed for match-quality ammo. They also offer custom case holders (based off your fired cases) for $31.50, shipped - see their FAQ or call. I've also had the Giraud and they offer blank case holders that the customer or third party can drill and ream with your chamber reamer (lathe work). Excellent product but much more expensive.

 

[oneshot.onehit]

I would have to agree with ELR researcher I really like my Wilson trimmer for the big stuff, I have used it with the following 375 Snipe Tac, 375 VM2, 375 Warner and the 416 Warner —- it is simple and very easy to work with and consistent in demands towards percision and consistency..


Cheers
Oneshot