Trail Boss and .303

lyman54

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Has anyone tried Trail Boss in .303 Brit? A 100% load is 15.5gr and 70% is 10.80gr as I tested it in a cartridge but didn't load it. Also what about pure lead cast bullets with or without gas checks. For power I did get a very good load with 39.5gr of Varget and a 200gr jacketed. But for plinking I'd like to try the Trail Boss. For the heck of it I loaded 50gr of Pyrodex P in a cartridge. Didn't see a hole in the target, most likely shot very low but quite a bit of smoke. And of course cleaning.
 
I did some loads with 55gr of Goex FFg under a 200gr cast bullet and they were over a foot low at 50yds if memory serves.
I use Trail Boss for loads in my Martini-Enfield quite a bit with 187gr cast bullets and need to set the sights to around 400yds to hit PoA at 50yds. I use the 1.9mL scoop from the Lee dipper set and it's around 9gr I think? Don't have my records handy.
 
Ive done 10gr of TB with a 180 cast from lee mold, no gas check. Its an ok load but switched to a reduced load of H4895 same set up and tightened the groups up at 50, both loads were like buckshot at a 100. makes a nice plinking load between 25 and 50 yds.
 
In an article from a few years back in Double Gun Journal, one of the contributors did a multi issue article on old guns, Damascus barrels, and pressures. He deliberately over charged some fine old double rifles and shotguns "just to see what would happen". He had a gun set up with a strain gage to see what the pressures were getting up to, and the Trail Boss loads behaved quite well, until he started compressing the powder. Then pressures spiked. Real bad.

Since then I haven't worried too much about Trail Boss for the few loads I use it for. I just don't compress the powder.

As for the pure lead, I wouldn't use it unless I was paper patching. I don't know how worn your bore is, but the possibility of stripping lead with pure boolits is too easy.

Try and find some wheelweights and mix at least a 50/50 blend.

What diameter bore does your rifle have? Might have to go with larger sized boolits, if the bore is worn. Or stay smaller with a tight bore.
 
In an article from a few years back in Double Gun Journal, one of the contributors did a multi issue article on old guns, Damascus barrels, and pressures. He deliberately over charged some fine old double rifles and shotguns "just to see what would happen". He had a gun set up with a strain gage to see what the pressures were getting up to, and the Trail Boss loads behaved quite well, until he started compressing the powder. Then pressures spiked. Real bad.

Since then I haven't worried too much about Trail Boss for the few loads I use it for. I just don't compress the powder.

As for the pure lead, I wouldn't use it unless I was paper patching. I don't know how worn your bore is, but the possibility of stripping lead with pure boolits is too easy.

Try and find some wheelweights and mix at least a 50/50 blend.

What diameter bore does your rifle have? Might have to go with larger sized boolits, if the bore is worn. Or stay smaller with a tight bore.

I wouldn't compress the powder either. The bore is .312 having slugged it and is in excellent shape. Perhaps a 50/50 mix is better. The Lee mold I have makes a .313 bullet but supposed to be .312 as written on the box. You think gas checks are needed?
 
You can try them without the gascheck and see how they perform. Both internally and externally. With the smaller shank, where the gascheck is supposed to sit, it acts like a boattail. I have never seen a boattail mold. Not saying there aren't any, just never seen one.

Try two different batches and see how they fly. One with gaschecks and one batch without. Personally I would test the gascheck first, then try the bare bum gaschecks, as they're more likely to lead the bore.

Slug your bore just to make sure the mold doesn't throw too small of a boolit.
 
Lee molds often drop slightly larger than the listed size I find. Lyman molds are usually closer to correct and all the molds I've gotten from Accurate Molds drop within .0005" every time. Different alloys will also increase in size different amounts. Pure WW alloy can increase in size up to 0.5% at times (so a .400" bullet could drop .402").

Boat tail molds aren't common because they usually have terrible performance. Cast bullets do not lend themselves well to boat tail designs. Many manufacturers have produced them in the past and discontinued them. Lee currently makes a 230gr .309" boat tail bullet and it gets really hit-or-miss reviews. Only ones that seem able to make them work consistently well are those who powder coat them.

Bullets designed for gas checks, when used without gas checks, are very hit or miss. It depends on a lot of factors that you can't really compensate for. I've never had much luck with them so stick to flat-base designs when I'm not running gas checks but others have reported no noticeable drawbacks from doing so. Most of the people I've talked to/read posts from who have them work well are using bigger bore stuff; .35 cal and up, mostly .44's and .45's. Maybe the bigger bores are less effected by having the rebated base with cast bullets? I haven't done enough testing to draw any conclusions myself.

I'd try some with and some without gas checks and see what the difference is like.
 
I use Trail Boss for fire forming my .303 British cases and for practice plinking with 100 grain 312 pistol bullets. I makes the brass butt plate softer in the summer when just wearing a t-shirt.

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I have gas checks but no longer have the press or sizer to crimp them on. Using a Lee Loader only so not sure about keeping the GC on. Or maybe it will stay in place inside the case mouth. I'll try the suggestions you guys put forth. I already made a 50/50 mix of WW's and pure lead. Thanks. All part of the fun of experienting.
 
I'm with Ed: I'm using 14.0gr Trail Boss and Hornady 85gr 32 cal pistol bullets. Accuracy is great at 50m, crap past that. A nice bang that doesn't kill your ears, your shoulder, or your wallet.
 
I wouldn't compress the powder either. The bore is .312 having slugged it and is in excellent shape. Perhaps a 50/50 mix is better. The Lee mold I have makes a .313 bullet but supposed to be .312 as written on the box. You think gas checks are needed?

Your mold will be designed for either flat base bullets, or for gas check bullets.
If it is for flat base bullets you can not use gas checks on them.
If it is designed for gas checks, then you should use gas checks, because they will shoot poorly without gas checks.
At the speeds you are indicating gas checks are not required.
 
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