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Gunsmithing Disadvantage of a short throat 338lm?

jonaddis84

Gunny Sergeant
Commercial Supporter
Full Member
Minuteman
Jan 27, 2009
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Toledo, OH
www.area419.com
I just received the prechambered Shilen Stainless Match 1-10" 338LM I ordered for my Savage 110BA. Getting it all set up I had two issues.

First was when headspacing, tightened on a go gauge, the no-go would still cam completely over. turned out the bolt was actually hitting the barrel before the gauge would touch the shoulder. This may have been due to my truing of the bolt face, but I didnt take THAT much material off, only what was necessary to clean it up. Turned a few thou off the bolt nose to correct this and good to go.

Second is the throat length. The ogive length of the 300gn scenars touching the lands is almost .100 shorter than with the factory barrel, to the point the rounds almost look goofy they are so short.

Now, I already loaded and fired up to 92.0 of H1000 with no pressure whatsoever. Since it doesnt appear I am going to need the extra case capacity of a longer loaded round, am I at any kind of disadvantage with these deep seated bullets?

This may play into somewhat of a favor when trying out the Berger hybrids, as I may still be able to mag feed them and load close to the lands.

While youre in here. Has anyone had to shorten a Savage firing pin before? Im cratering the primers slightly now with the trued bolt face. No punch throughs or cracks yet, should I even worry about it?
 
Re: Disadvantage of a short throat 338lm?

First, your headspace issue will not be a problem if your loading your own rounds, but taking .004" off of a bolt face could leave you with excessive headspace to the point that a no-go guage will cam over.

For a short throat, again handloading will allow you to kind of work around this. If you want to exclusively run the Beger Hybrids your short throat is going to take away a little more case capacity because you have a tangent ogive (more abrubt and further foward bearing surface) couples with a secant meplat.

In the grand scheme...with handloading...not a problem.
 
Re: Disadvantage of a short throat 338lm?

The primer cratering issue is not likely because you have an extra 0.004" of protrusion on the pin. It is far more likely from the fact that savage firing pin and pin hole relationships are "loose" to say the least.

A better fix would be to bush up that firing pin and then trim it back to 0.035-0.045" protrusion once that tight firing pin relationship is maintained.
 
Re: Disadvantage of a short throat 338lm?

Josh, problem is, here is a picture showing a primer before the bolt truing on the left and one after on the right. I mean the barrel also changed between the two, but that wont affect the primer. Every primer from 88gn up to 92 looks identical to the one on the right.

ETA: I just picked up on what you said now, and it would also fix the issue. I was just looking at it as the pin needed to be shorter, which I think would also fix it but would be a bandaid.

primers_1.jpg


As for the headspace issue waldo. I know for a fact the bolt nose was hitting the barrel face, because it was all scarred up, had my head hurting for a few minutes trying to figure out what was going on. After taking the few thou off the bolt nose though, the gauge was able to seat against the bolt face, against the chamber shoulder, and have about .005 free air between the barrel and the bolt face. I think Im all set on the headspace now.

Turns out I still wont be able to mag feed the hybrids, those fuckers have such a long ogive they are still too long for the CIP length mags the savage uses. I have probably .20" in front of the 300 scenars in the mag.
 
Re: Disadvantage of a short throat 338lm?

I should point out, as long as the cratered primers are not causing me issues, I could care less about it.

I was more concerned on whether I should have the throat extended slightly or not. My understanding of deep seated bullets was always that they take away from case capacity and thats about it, but Im not 100% on that. I just loaded some up at 93 and 94 gr H1000 and can still hear some powder shaking around in there, well see if I get any pressure signs.
 
Re: Disadvantage of a short throat 338lm?

Jon, you know one of the main advantages of the hybrids and thier secant/tangent ogive/meplat is to be more jump tollerant.

Ide see if you could get your mits on a box and see how they shoot while being jumped from mag. length...
 
Re: Disadvantage of a short throat 338lm?

I just so happen to have about 88 hybrids, Ive been trying to find the lands with them and they keep getting stuck in the rifling with my test case. I think Ill take your advise and seat them as long as the mag will allow and see what happens.
 
Re: Disadvantage of a short throat 338lm?

Ok, I need to find a new recoil pad for this PRS-2 before I can shoot anymore, holy hell my shoulder hurts! Ive got the extended pad on there and it still has literally no give to it, does anybody make a softer pad for this stock? My bony shoulders dont take it too kindly. (shooting with a can too)

I tried out 3 Bergers loaded at 92gr and seated max mag length, from 180yd the first two were same hole, but third flew left 1.5"...couldve been me though, i was getting hungry
 
Re: Disadvantage of a short throat 338lm?

Looking at your picture of the fired cases I have something else for you to consider. Before cleaning up the bolt face the primers flattened more and didn't creater because the case was being held against the bolt face by the extractor.

The second case after cleaning up the bolt face the extractor now doesn't hold the case against the bolt face allowing the primer to flow more.

You can shorten the firing pin but adjusting it but chances are you'll still have the createring because you cannot adjust the hold the extractor has on the case and the free space will allow the primers to still flow.

The only way to know for sure is to adjust the firing pin.
 
Re: Disadvantage of a short throat 338lm?

Since its a savage, I would buy a new bolt head and be done with it, the savage bolt heads are semi floating and center themselves when the bolt is closed, so there is no need to true it up, just my .02