Importance of forearm / reciever gap question.

pete · Post by **pete** » Sun Jul 04, 2004 2:05 pm

I know I should send this directly to Shiloh but it's a holiday and I have some time to shoot so I'm hoping to get some info.
My situation is that I'm having trouble getting my #3 45-70 shooting good 200 yd. groups. I've tried 3 different bullets five different primers various amounts of 2f Goex varying amounts of compression and the best I can do is 5 shot groups that are 6 inches. Sometimes 4 shots will go into 2.5 to 3.5 inches. Some groups are 12 inches. I'm using a MVA vernier and 111 globe front. I was using new brass then tried fire formed to no avail. I plan on ordering one more mould. Most groups have a bigger vertical dispersion.
Today I rembered that there was some talk about wanting a slight gap between the forearm and reciever. I tried to slip a .004 piece of paper in and couldn't so I took off the forearm and applied a thin film of my wifes lipstick on the reciever and put it back together. When I took it apart there was some lipstick on the forearm low on the hammer side.
My question is. How important is this gap thing? Is it a real issue or is it something that's blown out of proportion?
I don't want this to look like I'm being negative toward Shiloh in any way I'm not. The only reason I am posting here is because I was hoping to get some input and do some more shooting tomorrow. Thanks.

wwben47 · Post by **wwben47** » Sun Jul 04, 2004 2:25 pm

pete,
I will be very interested in what you learn about that gap..I am getting a #3, 45/70 in about a week myself..I cant wait to get started! Good luck!

MikeT · Post by **MikeT** » Sun Jul 04, 2004 8:53 pm

pete,
The surest thing to do is shoot another 500 times to see if it makes any difference. I'm guessing that the groups will get smaller the more you shoot that rifle.
Keep on hav'n fun!

Sharpsnut · Post by **Sharpsnut** » Mon Jul 05, 2004 2:36 am

First of all,the forend contact on the reciver only really matters on shot string long enough that the barrel really warms up,thus the barrel swells a bit and pushes back the forend against the barrel.I have shot many '&$ Sharps both ways and there is not much difference.If your Shiloh were mine,I would leave it alone for now.

The real question with yout groups is-are you a GOOD iron sight shooter??

Also ,quality sights and front apertures matched to a target that can be SEEN conistently are needed by folks that have young,sharp eyesight.

What type of buttplate does your #3 have? Do you have a recoil pad either on your shoulder or a add on velcro or rubber type on the gun?
If you don't ,you need one as the recoil on these guns is very cumulative and WILL sneak up on you over time...

I ask this because flinching is often overlooked and is a BIG cause of fliers shooting BPCR groups.
I am not talking about a massive .450 Weatherby mag type flinch either,merely tensing up at the grip at the moment the shot breaks can cause shots to go wild due the the long time of flight of BPCR rounds.

Also do you have good benchrest technique? It all ads up..

BTW, you should limit some of the variables in your load components.I would stick with some Brand of Regular LR rifle pimers and stick with them until you find a powder charge bullet combo the gun likes.THEN fine tune things like primers,etc.

One last thing,When you load your bullets how deep are they seated? Does the first driving band engrave into the rifling slightly??
Most rifles shoot better with a bit of engagement of the bullet into the lands..

Just my .02 worth..

Post by **Kirk** » Mon Jul 05, 2004 11:12 am

Hi Pete, The way to find out if the forearm is causing you problems is to shoot the rifle minus the forearm. If the rifle shoots better, then we need to look at the forearm. My father in law shoots a 45-70, when first starting he took forum advice and compressed a lot of goex and it shot terrible. I had him drop enough goex to seat the bullet without compression, the round didn't travel very fast but it became accurate. What was happening, was he wasn't managing the recoil very good. Now he is starting to sneak his load back up to gain velocity and everything is working a lot better. Hope this helps. Thanks Kirk

HvyMtl · Post by **HvyMtl** » Mon Jul 05, 2004 8:48 pm

Hi Pete

After you do what Kirk suggests, go to page 5 of the Support forum under modifying the base of the forearm. It's about 1/3 the way down.

Good luck

Ken

pete · Post by **pete** » Mon Jul 05, 2004 9:14 pm

Thanks for the replies. They're gonna help I know. I think I was premature in thinking the forearm might be an issue. I have loaded bp hunting cartridges for a couple of years but this match stuff is a tougher matter.
I definately need to work on my bench shooting technique as well as manage recoil better like Kirk and Sharpsnut have suggested. That will require more shooting as well as starting lower on the power scale when I get a good bullet.
I tried Lyman's 457132, Saeco's 745 and for grins my hunting bullet Lyman's 457193. I don't think my rifle likes the 457132 since when I shot it with 63 gr. / .125 compression I had a hard time getting it to hit the target board and had a keyhole. Medium compression loads .160 - .240 eliminated the keyholes but only shot around 7'' groups. I cast these and although my casting needs work they should have done better than that. These were +- 1.5 grs. (still trying for the +- .5 gr.).
Next I tried the Saecos that I bought at a gun show awhile back. Sometimes they shot better. I even tried the heavy compression route and they shot worse with a 12 in group. I admit to being leary about these which probably accounted in part for the performance. A major culprit is the bullets themselves. I used these before in my Lonestar for a silhouette match to see if I liked the game and these shot pretty good. Then I bought some more and these are the ones I shot lately that gave me trouble. I knew they weren't great but until I did a closer inspection I didn't know they were this bad. I found voids in them when I poked around on them with a pin some of which were pretty good sized. I then shot some in my Lonestar and they hit all over. I had to move the target to 150 yds to get groups like my Shiloh gets at 218.
So I'll say it to myself. " It's the bullets stupid". It's just that the earlier ones shot ok which I guess through me off.
Thanks Kirk for the tips. I'm going to get another mould and start over again.

Sharpsnut · Post by **Sharpsnut** » Wed Jul 07, 2004 7:25 pm

pete,

what alloy are your bullets made from??

pete · Post by **pete** » Wed Jul 07, 2004 9:29 pm

Sharpsnut; The 745's I bought are supposed to be 20-1. At least that's what they're shown to be. The 457132's I casted are 20-1 too, from Midway alloy. I'll have to tell the guy at the next gun show about these bullets.
I called Buffalo arms and am ordering a Lyman 457125 and some more alloy. Hopefully my rifle likes it better. I want to keep all the lube grooves covered so maybe this design will work better than the postell. What do you think? I almost ordered the 745 mould but heard more than once that the lube grooves aren't good enough. I haven't shot them enough to know for sure and didn't want to take the chance, but I did notice there didn't seem to be as much lube around the bore at the muzzle as there was with the postell.
When I find a design the rifle likes I may get a custom mold of the same design. Does this sound like a logical way to go about things?

Sharpsnut · Post by **Sharpsnut** » Fri Jul 09, 2004 12:50 am

First of all,no matter WHAT bullet you shoot in your rifle,you should NEVER rule out something that might increase accuracy if needed.That applies to seating the bullet out so that the first driving bands touch the lands ,thus exposing lube grooves.

If you want to load hunting ammo great with no lube grooves exposed -great.Seat the bullet so the case mouth is just past the driving bands and give 'er a good,roll crimp.If you want target grade accuracy,be prepard to get that bullet out much closer or even slightly engaging th lands,period.

As to the #745 Saeco bullet,I have used it for years with great success.I shot myself into Master class with it last year while shooting a VERY fast ,hot load of FFFG Swiss behind it.Only when the humidity reached very low levels-30% or less with 85 degree plus temps did my barrel seem to need more lube.

I know also know three ther Master class shooters here in the Dodge City ,KS area that use the #745 Saeco bullet.Our NRA regional match has been won with that bullet as well as the Nationals in 2002(Joe Scott)..

Also, the Saeco molds are better quality than the Lyman and easier to cast with.I would try the Saeco first...

pete · Post by **pete** » Sat Jul 10, 2004 10:58 am

Sharpsnut; Thanks. You're right . If I have to seat the bullet out I guess I'll have to. I'm gonna try not to but if it comes to that I'll do it. As far as temp and humidity goes. Temps in the 80's and 90's with humidity in the 30's isn't unusual at all here. In fact humidity at 30% is about average if not a little high many times, excluding cold fronts, thunderstorm periods etc.. Even in the winter it's pretty low.

I'm gonna try the govt. style bullet and see what happens. That'll give me two different styles to see which one it prefers.

KHR · Post by **KHR** » Sat Jul 10, 2004 12:34 pm

pete,
that lyman gov bullet works well. Keep working with it. I use 61g swiss 1.5 and a .30 wad almost no compression. I only neck size and have a expander plug from buff arms that gives me .001 neck tension. I found that shooting the same way each time helped my groups more than anything else. Try using the same pressure position on frint rest etc every time, might help!

keith

pete · Post by **pete** » Sun Jul 11, 2004 10:47 am

KHR: Thanks. I'm gonna give the govt. bullet a good workout and see. It's shot good for who knows how many people. Lube definately won't be an issue with it.

I'm sure I need to work on my shooting style (what little I have) too.

That expander plug might be an option too. My little Lonestar rb shoots good with the standard plug but it's chamber is quite a bit bigger than my Shiloh's and I can't even get close to chambering a round in the Shiloh sized for the Lonestar. I have to size brass quite a bit more to chamber rounds in the Shiloh although I only size just enough to chamber a cartridge. I guess what I'm saying is that I'm sure brass springs back a little when expanded and when a case that's a little tighter to begin with springs back it might need a little bigger expander. Thanks

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Importance of forearm / reciever gap question.

Importance of forearm / reciever gap question.

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