Breech seating?

[softpoint]

I cobbled together an adjustable breech seater for my Browning BPCR in 45/70 today. I have been getting quite good groups(IMHO) out of this rifle, with some 5 shot groups going under an inch at 100 meters. I am using the el cheapo Lee 500 gr. PB mold, and I know it isn't the best, but a better mold is in the future. I do have some fliers that open up a lot of my groups to almost 2 inches. And I must admit I am shooting smokeless powder, too. 21 grains of 2400 with a pinch of poly filler. One of variables I wish to eliminate is neck tension, since I can feel differences in the cases when I run them in the expander die. No neck tension at all should solve that. I dropped a boolit in the chamber, tapped it lightly in until no light from a bore light at the muzzle end showed around the boolit at the breech. I used a soft wood piece of 7/16 dowel rod to tap it. I then made my breech seater out of a empty case with a .308 case cut off and inverted in the 45/70. made this a few thousanths short, and then ran it back in the 45/70 full length die. Drilled out the primer pocket and tapped with my stuck case remover set. Cut a 1/4 inch diameter threaded rod to be just below the casehead surface when bottomed out, and ground a screw slot in it. Adjusted it out to seat my boolits at the depth I had determined. Un sized fired cases out of this rifle were decapped and re primed, charged with the 2400 powder, and a tuft of polyfill poked in to fill,and hold the powder in the case.
Has anyone here experimented with breech seating? (I haven't fired any of these yet, will be tomorrow)Did accuracy improve? This is just an experiment i thought would be fun.:D

[montana_charlie]

Breech seating the bullet has been practiced by many, for a long time. But, I have never heard of anybody doing it while using smokeless powder.

I can't imagine how any published data for the 45/70 can be applied to a configuration that makes such a drastic change in the effective volume of the cartridge case.

CM

[softpoint]

In this instance, the volume changed very little. The fixed ammunition I was using with this boolit seated to the crimp groove was very nearly touching the rifling. I have read of people doing this with smokeless, but never saw any posted results. And I'm sure some combinations showed different results, We will soon see, I am going to make time to shoot 10 of these this evening.

[rhbrink]

Breech seating the bullet has been practiced by many, for a long time. But, I have never heard of anybody doing it while using smokeless powder.

I can't imagine how any published data for the 45/70 can be applied to a configuration that makes such a drastic change in the effective volume of the cartridge case.

CM

Ever hear of Schuetzen shooting? Go over to the ASSRA web site and take a look around, you see a whole bunch about breech seating smokeless.

RB

[softpoint]

I did finally get a chance to shoot the first ten rounds before dark.I may have shrunk the group size overall a tiny bit, but since i didn't average my previous groups, it's hard to tell. And, I'm not sure about my own ability to shoot groups any smaller than 1 1/2 " or so at 100m. with iron sights, even though they are pretty good irons. At any rate, they certainly shot as well as ANY other load I've tried in this rifle, and it is interesting (for me,anyway) to know that I could reload very accurate loads for this gun with no dies, just need a way to seat primers, a powder scoop or measure, and case life would be a very long time! The poly fill keeps the powder in the case so a box of cases could be loaded ,(I'd keep the case mouth's up)I indexed the cartridges the same in the chamber each time, as well. They are Federal cases, and I put the F-C to the top.

[montana_charlie]

Ever hear of Schuetzen shooting?
Yes, I've heard of it. Don't know much about it. I've heard just enough to have an impression that 45/70 is not considered to be a shuetzen-friendly caliber.

If you are one of the 'informed', why don't YOU provide the man with some information?

[rhbrink]

I did. Go over to the ASSRA web site and look around there is lots of info on breech seating. And the 45-70 is not generally used in the Schuetzen game. Too much recoil for long strings of shots especially offhand.

RB

[softpoint]

I did. Go over to the ASSRA web site and look around there is lots of info on breech seating. And the 45-70 is not generally used in the Schuetzen game. Too much recoil for long strings of shots especially offhand.

RB
That's true, 45/70 is not needed or desired in that competition. And I am not loading these rounds for competition shooting at all, just curious to see if accuracy could be affected one way or the other.Also, people shooting rifles that have very expensive brass might consider loading target loads this way, as it should greatly increase case life...

[Gtek]

If seating those big boys was the ticket the breech crowd would not be in the 32-38 hole crowd, 25 and 27 for the hard heads. Five under an inch @ 100. What is your bore pushing routine during string? Boolit construction (alloy), lube, seating depth? I would feel I was so close with what I had and tweeking one item at a time do define outcome. My favorites are my Hoch 203 and Borden 207 25-1 at .323" tapered placed .060" in front of a 32-40 case with 14.2 of 4227 with pea of Kapoc. If no one has told you it appears you leaning into about stage four, takes one to know one. Welcome to the madness! Gtek

[bbqncigars]

softpoint,
That's damned good shooting with irons. I'm really happy when I do that with the Sharps with any load combination.

[softpoint]

softpoint,
That's damned good shooting with irons. I'm really happy when I do that with the Sharps with any load combination.
Good to hear that others are getting similar accuracy. I believe 1.5 to 2 might be my limit at 100 meters. Some groups are better, and then, of course there is that occasional boolit that seems to acquire an attitude right after it leaves the muzzle? At any rate, It is interesting to hear what kind of accuracy others are getting. Breech seat reloading seems to be accurate, requires no dies, just a way to de-prime and re-prime, and a powder scoop, once a load has been developed.

[rhbrink]

Once you approach MOA there are some areas that you need to really improve on. Number one would be wind flags, then bench technique,and of course consistency in "ALL" aspects of your routine, brass, seating dept, powder, the list goes on forever.

I have been breech seating for the last two years so I'm far from a expert that is why I suggested to go over to the ASSRA web site there are a bunch of good people there to help. For myself I've had a lot of good coaching and help from those guys.

One thing I can say for sure is that you need to seat your boolit up into the barrel far enough to seal the base of the boolit in the barrel. One way to visual check this is to seat a boolit the hold the rifle up to a strong light and look through the chamber and see if you can see any light if you can move the boolit foreward until you cannot see any light. The Schuetzen rifles have a throat cut and a boolit mold custom made to do this, makes it much easier to accomplish. A sort of rule of thumb is that you need approximately 50% of the base of the boolit engraved with rifling. When you achieve that experiment with powder charges and primers to get the best accuracy possible. Once that you are satisfied that you are shooting as well as possible move the boolit foreward about .010 and try again it may get better or it may get worse, if it gets better move it foreward again after a couple of times you will find that you may need to readjust your powder charge.

It takes quite a lot of work and shooting to accomplish all of this but when you start approaching 1/2 MOA at 200 yards it then becomes very worth while.

One of the funist parts of this is when I'm shooting at the range and somebody new walks by and sees what I'm doing they are simply amazed and say that they have never even heard of doing anything like that. Some even question the safety of such practices, I always say that this has been going on since the 1880's and nobody has had a problem yet. One other thing that I will say is that while your doing this it is very easy to get distracted especially when people are around and asking questions. So develop a routine and as soon as it is interrupted stop and start all over again. It never fails that someone will say "OH don't let me bother you but" I just stop all actions and try to explain what I'm doing and start all over again. I've had more that a few really fine groups going ruined this way but that a small price to pay. Maybe some day you might convert someone over to cast boolits even Schuezten.

Be carefull and good luck!

Richard

[Gunlaker]

I do find that shooting old single shots does attract people for conversation :-). Particularly if you are doing "unusual" things like shooting paper patched bullets or breech seating. The other day I pulled the trigger only to hear a click. I'd seated the bullet but got distracted by a few questions and forgot to chamber a charged case! The idea of starting your routine from the beginning following any interruption is a good one.

Chris.

[rhbrink]

Yep! Done that one a few times also forgot to seat a boolit then seat charged case, makes for a very hollow sound and a very dirty bore. The absolute worst is a double charged case that is something that you have to be very carefull for. There has been a few old Ballards that let go at the seams because someone double charged a case. But you have know or should know that these were only designed for black powder and were not a very strong black powder action to start with 125 years ago.

I always store my case upside down when not in use and then when ready to charge with powder I tap it upside down a couple times and then charge the case and seat it in the action. If something disrupts this final step I dump the powder back in the hopper and start over again. You absolutely cannot be too carefull.

I have been told that there are getting to be few ranges that will not allow charging cases with powder on the firing line. You must bring precharged cases to the line to shoot. That's OK fine and dandy but what keeps someone form double charging a case back at his or hers loading station? I suppose that would cut the odds down somewhat and I always check my loading blocks with charged cases with a light or a measuring tool of some sorts before seating boolits anyway. You just cannot be too carefull I know that I'm starting to sound like a broken record but BE CAREFULL!

Richard

[Gunlaker]

I've only been breech seating with black powder so I'm not too likely to double charge a case :-). However I will probably give smokeless a try at some time. I'll probably adopt your process then.

Chris.

[softpoint]

Since this isn't a small bore (.32/40, etc) I think anything close to 1 moa is probably the limit of the equipment I have. And with iron sights it is quite likely my limit as well. I might be able to improve a little, and since I made my breech seating plug adjustable, I might start by screwing it out just a tad, and seating a little deeper. I'm not trying to win cast bullet benchrest matches with this 45/70, but just trying to get it to shoot as good as I can. It's an "out of the box" Browning BPCR rifle,No set trigger,but does have a Badger barrel.

[HARRYMPOPE]

I did. Go over to the ASSRA web site and look around there is lots of info on breech seating. And the 45-70 is not generally used in the Schuetzen game. Too much recoil for long strings of shots especially offhand.

RB

true-i shot with Dave Heber from BC in a couple of CBA matches.He used a short 30-30 x .375(375 Heber) and it was no advantage over the 32 Miller short or 32-40 because recoil became an issue with the heavy bullets he used.

George

[Starvnhuntr]

i hand seat my boolits over a powder charge that is compressed to a predetermined depth. doesn't that accomplish the same thing if you figure the seating depth ahead of time. the best group i have ever gotten is 1.25 inches@ 100 yrds. this is with a miroku high wall 45-90.

[softpoint]

i hand seat my boolits over a powder charge that is compressed to a predetermined depth. doesn't that accomplish the same thing if you figure the seating depth ahead of time. the best group i have ever gotten is 1.25 inches@ 100 yrds. this is with a miroku high wall 45-90.
That ought to be very close to the same thing, although the seating plug I am using pushes the boolit pretty firmly into the rifling,at exactly the same depth each time, the action of the 1885 cams it into place. May be slightly more consistent than depending upon the powder compression to seat. I don't know that, though, your method seems like it would be good, too, but I am using 21 grains of 2400 with a poly filler, so I can't do that with my particular load:)

[MT Chambers]

Both my 32/40 and my 25/20 single shot shoot better when breach seated, both use tapered bullets, and I still have/had to try different loads, dif. primers, seating distance, bullets hardness (30-1 seems best).....I enjoy breach seating.