accuracy vs powder

[huck]

Anyone have any experience with a change in load/powder DRASTICALLY affecting accuracy?

I decided to try Triple 7 in my GPR. Used to use Pyrodex RS (100 gr - for hunting). Tried 90 gr. of 777. I was spraying bullets all over at 100 yds. Moved back to 50 yds., and I'm still spraying them all over (about a 7 inch pattern). I used to get 1-2 inch groups at 50 yds., and 3-4" groups at 100 yds. I didn't have any Pyrodex with, but someone else at the range did, and offered me some. Two shots in a row with 100 gr. of pyrodex at about the right elevation at 50 yds. within 1 inch of each other. Then I ran out of time and light. So I can't guarantee that a 3rd or 4th shot would have been in the same tight group...but it certainly looks like I have an issue with the 777.

I'm not a great shot...but I can hit 1-2" groups with my scoped, sporterized Mauser. And I have been able to hit 3-4" groups with the GPR, like I said. And I was using a sandbag and holding the gun FAIRLY steady.

Has anyone else seen this kind of variation between loads, or with 777 in particular?

Oh...I'm shooting patched round balls - .54 cal. Pre-lubed patches. Nothing's new except the powder.

Any thoughts?

 

[huck]

Another related question: Do many people experience the first shot being erratic? How do you deal with this in terms of sighting the gun in? And how do you deal with it when you're going to be hunting, and the first shot is, hopefully, the only shot?

 

[vanstg]

Triple 7 is hotter than Pyrodex or real black powder. Maybe it's burning your patches.

 

[gordy]

What twist bbl. do You have on the GPR?? If it's the faster twist,You may be strippining the rifleing.If the patch is being destroyed by the extra heat of the 777 that would cause blowby and ruin rhe accy.Next time to the range try a buffer under the patch!Wonder wads work well,I use hornets nest under heavy loads and it works for Me. :hmm: :thumbsup:

 

[brushbuster]

i am thinking you are loading your first shot without wiping the oil out of your barrel with alcohol.are you using the same lube to coat your barrel when putting it up?
if not you are changing the friction properties of your first shot compared to your next shot/shots. try running an alcohol patch to remove oil and dry out the barrel then load.
also are you cleaning between shots? depending on which
lube(s) you are using ,the presence of fouling can change your point of impact :thumbsup: :results: :imo: :m2c:

 

This is not unusual at all. Changing any part of the componant mix can change point of impact.

You have changed powders. You are working up a new load just as if this were the first time you were firing the rifle. The only difference being that you have the old reference to measure progress too.

By the way, you do have a choice! If your rifle does not like T7 switch back to Pyrodex. Some guns will not shoot just anything you stuff into them. Nothing the matter with them, they just have favorite meals.

:m2c:

 

[mec]

Ive used 777 from the same measure setting as fffg or pyrodex p in revolvers and pistols and have seen very erratic performance- velocities varying as much as 250 fps extreme spread. Loaded to lower volume,- to produce the same velocities as pyrodex p, extreme spreads contract and accuracy is very good. I don't know how this translates to rifles.

 

[sneakon]

I thought I would try the switch to Triple Se7en, but had similar results to Huck; just could not get consistent patterns no matter the load. Changed back to pyrodex at the end of my shooting time and had much more satisfying results. Bought some Goex on my way home and can't wait to try it out to see how real black powder compares to pyrodex. I really envy you guys that can shoot just outside your back door. I would do allot more shooting if I didn't have to drive for an hour first.

 

[Rat]

Try some Swiss BP if you want the best of both worlds...the consistancy and reliability of black, and almost as clean burning as the substitutes.

Rat

 

[ehepp]

I have read that to match a 100gr. load of Pyrodex you should load 80gr. of 777, could be the difference.
:hmm:
I had a similar problem shooting my GPR with Pyrodex Select. I believe that the larger granuals of the select caused inconsitent loads and my accuracy suffered greatly! :results:

 

[huck]

vanstg and gordy - ya know...I didn't CHECK my patches - didn't even look for them. That's certainly a thought.

It's got a 1 in 60" twist, basically ideal for PRB - maybe the T7 isn't...

Brushbuster - I AM doing things a bit inconsistently there. I use regular gun oil to store the gun - maybe a bad idea. Then I push a patch through it to dry it when I'm ready to shoot the first time, fire a cap to make sure the nipple and flash hole are clear, load it with pre-lubed patches (TC bore butter) and a round ball, and fire it. I've found best results running a cleaning patch every shot. But maybe I need to find a more consistent system. Another guy at the range, who shoots BP some, too, advocated, for hunting, firing one shot through the gun, brushing or patching the barrel, then loading it for the next morning's hunt - so it's already been "pre-fouled". And then sighting it in ignoring that first, erratic, shot...rather than trying to guess where that's gonna be. The first shot's the one I want to be accurate!

As for the T7 vs Pyrodex...or switching to real BP, I think I'm gonna pick up another bottle of Pyrodex, go to the range and see if I can improve on the T7 loads, or maybe try Gordy's suggestion of adding wonder wads as a barrier to save the patch, and, if nothing works, make sure the Pyrodex is still consistently working well. Go back to that, if necessary. May have to try some good old fashioned BP sometime, too.

Thanks for all the advice, everyone! Any more thoughts will certainly be considered.