Setting Expectations

[Guy La Pourqe]

Hey Fellas.

I was wondering if somebody could check my homework and give me some idea of where I should be. My rifle is the heavy barrelled, 32" Pedersoli Remington rolling block repro. Today I was shooting 515 gr. Money boolits off the bench and they went into about 3-1/2" inches at 100. Sights are Lee Shavers front and back, midrange soule sight on the rear and the multiple insert hooded spirit level up front. The load is the Money Point, sitting on 34.5 gr. of 3031, with 1.5 gr. Dacron filler. In your scholarly opinion - should I be expecting better accuracy? The boolits are moving about 1200~1300 FPS, and I am getting a little lead fouling.

The next issue is powder fouling - after the first shot there is more crud and corruption in the bore with unburned powder residue. Can that be an accuracy issue too?

As always, your two cents is sincerely appreciated.

[country gent]

Not to sound mean or rude, 1st how well do you see the sights on the rifle? I would continue tuning the load at 3 1/2". Powder fouling can cause accuracy issues as can leading in the bore. What lube are you using? Another concern with these style rifle is bench technique and the pressures on them.

What is the bore and throat dia of your rifle and what size are you sizing bullets to? How much neck tension and or crimp do you have? How hard is the bullet? Has the brass been fire formed or is it full length sized.

When you say powder fouling is it actual fouling or unburnt powder? Sometimes a crimp will help with powder burn as well neck tension also experimenting with different primers may help.

[koger]

x2 on the neck tension. I have shot many pounds of 3031 thru a 45/70, and the fouling left is minimal, don't look great but has never hurt my accuracy. And I am talking shooting rifles with scopes on them, to work up the best loads. I have a Marlin first year guide gun, that I run loads to hot for most single shots, and it shoots a tight cloverleaf at 100yds with 300jhp,or405 gr fn, with 3031 as the powder. You rifle might not like it, but it shoots great in the 9 45/70s I have.

[RedlegEd]

Hi. In addition to the excellent questions posed by country_gent and comments from koger, I'd recommend you have a look at these two videos. The first discusses barrel harmonics, which may have an impact on your groups depending how you're resting your rifle on the bench. The second video discusses bench technique (among other things.) Skip ahead to 15:00 for some guidance on shooting a "heavy" rifle from a bench. Hope these help. Ed

https://www.youtube.com/watch?v=HFFJAGeYj1A

https://www.youtube.com/watch?v=xle24smVK0s

[smithnframe]

Try blackpowder!

[Guy La Pourqe]

Well thanks for weighing in, boys!

The bore slugged at .459; and my moulds drop at that diameter too. (They are Boomer moulds, out of Saskatchewan. Is he still in business? That guy was awesome to deal with...). Lube is home brewed, I pan lube using the recommended mixture of beeswax, olive oil and Crisco. I think it is doing the job - after a shoot, there is a thin film of liquified lube around the crown of the muzzle... if that means anything. And it is indeed lead fouling - I have seen tiny chips and shavings on the cleaning patches but in fairness they are moving a bit fast, at around 1350 FPS which is a tad faster than I want to go. Lead mixture is about 20:1. Bullets are shot as they fall from the mould. I only crimp the bullets enough to keep it from moving around, and try to keep them as light as possible. The powder fouling is indeed unburnt powder. I trim my brass at maximum length - 2.105" if memory serves. Do you guys neck size on your BPCR sniper rifles? What kind of accuracy at 100m are you guys getting?

As far as vision goes - I am an old fart, but I can make the sights out with the post and bead insert in the front sight. With modern rifles up to the task I can and do go sub MOA... but that is with scoped sights.

Thanks for those vids Red Leg! And thank you all for helping out!

I have tried black powder... and fully intend to move to the more manly propellant as soon as other issues are nailed down.

[samari46]

My Ruger 31 in 45/70 slugs out at .459 I only have one gas checked bullet mold. It too casts at .459 You would worlds ahead going to a fatter bullet at least .002 larger or even .003 larger. Which I plan to rectifiy as soon as I can. And reduce your load slightly. Frank

[1Hawkeye]

Try a little larger diameter bullet say a .460-.462 without the dacron filler and maybe seat the bullet out a bit further say 5 to 10 thousands longer for your overall length. 3031 always leaves the granules but that shouldn't be a issue. The other thing to try is take the powder charge up to 38.0 grs it might be the 34.5 grs doesn't give enough speed to stabilize that long bullet. The original 500 gr gov't load was about 1180 fps.

[marlinman93]

I personally have never had great accuracy with 3031 in any .45-70 I've owned. I think 4198 is a much better choice. 3031 is always a dirty powder, with a lot of crud and residue left in the bore. I don't think the residue hurts accuracy, but not burning completely isn't my idea of a good powder. If you want to use 3031 you might need to up your charge a bit to get good complete burn, and better accuracy. 3031 isn't a great choice for mild loads.

[Kraschenbirn]

+1 on the 4198 (and AA2015, with some boolits, is even better). Mine is an older Pedersoli RB...30", half-octagon barrel...with exactly the same sights as yours. Off sandbags...if I'm having a 'good' day...gun will print under 2 MOA all the way out to 300M using a 450 gr RNFP launched at 1280 fps. My barrel slugs .4575x.450 and I load boolits 'as cast' (.460-.461) and pan-lubed with Emmert's.

Bill

[country gent]

While time consuming to do in your case it wont take a lot. You can lap the mould up a little bigger with out a lot of trouble here. A few good cast bullets from the mould and some very fine polishing compound and a little elbow grease.
Another option might be to ask for some .460-.461 dia bullets on swapping and selling to test first nd see if they help. if the larger dia does improve accuracy then lapp out your mould.
Here is my procedure for doing this. Remember to work slow and check often. When lapping a mould .001 removed is .002 on bullet dia.
Cast 3-4 good bullets and set aside to cool let blocks cool also.
I use 1/8" key stock cut 1 1/2"-2" long for the driver stem. Drill a blind hole on center to just allow the stem in snug. drill as deep as possible with out breaking thru. Epocy the stems into the holes. You now have your lapps.
Put a small smear of compound on a flat steel plate and roll lap between 2 plates to impregnate surface with compound. A drop of light oil in the lapp.
carefully and gently insert lapp into block and close.
Use a tap handle to turn and with a tapping motion rotate back and forth 1/4 turn 3-4 times rotate 1/4 turn and repeat thru 2-3 rotations.
Clean blocks preheat and cast a few bullets when cool check for size and repeat lapping as needed to desired size.

For your needs here I would recommend starting very fine on the compound. 800 grit lapping compound, diamond lapp compound yellow concentration, flitz, tooth paste, green rouge. There is a method to grade your own lapping compound from grinder ash but its a slow process to get where you need to be.
As you lapp the compound breaks down to finer grits improving finish The application of light oil helps in this and lubricates the cutting action.

I use a Meacham bushing die for my bpcr rounds and only size down to roughly the base of the bullets location. ( I load BP so need the room also). In your case this would leave most of the case at a close fit to your chamber only the neck will be "looser".
In my case with BP the bullet rests on the powder charge wad stack and cant move. I shoot a very light neck tension. Bullets can be turned and pulled by hand / finger pressure. I also hand seat the bullet then set neck tension with the bushing die around the bullet.