Is my inaccuracy in my loads or my shooting technique?

[ltrmc02]

I have just recently started reloading and am trying to develop some loads for a couple of different .308 rifles and I am not getting very good results but since I have also just started shooting from the prone position off of a Harris Bipod I'm not 100% sure that the inaccuracy is in my loads or whether the recoil is having a big affect on my shooting from the prone position.

The rifle I'm mainly concerned with getting more accuracy from is a Rem 700 Tactical Compact (XCR) 20". I have shot some really tight groups with it when I first got it using some Federal 168gr match rounds but was shooting off of a bench with the rifle seated down in a sack of corn. I don't recall the MOA of the groups but they were tight and I was very pleased with it. Now that I'm trying to develop a load for this rifle and now shooting off of a Bipod I've tried 3 different bullets, different charges and different seating depths and am getting between 1.6 and 2.0 MOA which is no where near what I have done with this rifle previously.

Now on the other hand I've loaded several different combinations for my 22-250 and also shooting from the prone position and I always stay around the 0.48 to 0.51 MOA with that.

I know I should go buy some more Federal Match bullets and try them from the prone position or either try my reloads from a bench and corn sack but at the moment that's not feasible so I'm just asking for thoughts from you guys that have done more prone position shooting and more reloading of .308's than myself.

Just another thought to add in, my spread is mostly all vertical yet the last batch of loads I shot only had a velocity spread of 9 fps per my chrono.

 

[farout]

Barrel may be jumping some. With in rifle "down in a sack of corn" you might have been masking a little bit of jump with the rifle. Most seem to jump left a little from the bullet torque. Also might have had the rifle balanced on the corn sack differently from how it is balanced on the bipod.

Might try keeping shoulder pressure constant on the rifle when firing, if the rifle is back heavy due to short barrel and placement of the bipod, you can get vertical, if shoulder pressure is not constant.

Is the rifle jumping at all with the bipod? If the bipod is leaving the ground, that is not good. Try holding the rifle in a more conventional manner with the left hand holding the rifle stock just front of where the recoil lug is.

 

[bill123]

What load are you using? I recently tried to work up a load with Varget and 155 gr Lapua Scenars. I was lucky to get 1 1/4" groups. I switched to 175 gr SMK's and when I was on, my groups where 3/8" or better. Your handloads should at least match the performance of the 168 gr SMK's.

 

[royinidaho]

Go here: Bugholes from Bipod

and here:

http://www.longrangehunting.com/forums/f116/importance-being-solid-91149/

Then let us know how it's going.

 

[BrentM]

Verticle to me says you are not lining up behind the scope consistently due to the prone position. My guess is you have to lift your chin up from the cheek rest to get proper alignment. ??

 

[mrb1982]

Bugholes from Bipod

Man, that is an impressive hole there. Just a little different technique than I am used to reading about.

I think one of my downfalls is inconsistent cheek weld. The more I read, people really tend to lay into their cheek weld heavier than I do. I need to put a DE cheekpiece on my stock, and really get a good cheek weld. Seems like when I get a good cheek weld or much hand pressure, my groups start scattering now. Man I have a lot to learn!!!!!!!!!

 

[boomtube]

"Is my inaccuracy in my loads or my shooting technique?"

Probably. ??

 

[trigger puller]

You are headed in the right direction, remember to concentrate on technique and dry fire alot. Once you are comfortable in the prone then start looking at your loading. There are several videos on prone shooting, use your googlefu good luckgun)

 

[ltrmc02]

What load are you using? I recently tried to work up a load with Varget and 155 gr Lapua Scenars. I was lucky to get 1 1/4" groups. I switched to 175 gr SMK's and when I was on, my groups where 3/8" or better. Your handloads should at least match the performance of the 168 gr SMK's.

Since I have just gotten into reloading and smokeless powder is nearly impossible to acquire from what I'm seeing I bought the only powder I could find said to be OK for .308 which is IMR 3031. Once looking up loads for it I see it is a bit faster burning than the more popular powders like Varget and Reloader 15. I'm trying to work up a load just for my 20" with this powder as my thinking is the faster powder may be better in a shorter barrel but I may be wrong in my thinking? I've tried 155gr Amax and 168gr Nosler Custom Competition and have set them at different OAL and changed the charges a little. I'm starting to get flat primers at around 2530 fps with the 168's. Just looking at load charts I see that IMR 3031 builds more pressure than other powders while achieving the same velocities so it's not my choice of powder, just the only thing I could get my hands on at the time.

 

[ltrmc02]

Barrel may be jumping some. With in rifle "down in a sack of corn" you might have been masking a little bit of jump with the rifle. Most seem to jump left a little from the bullet torque. Also might have had the rifle balanced on the corn sack differently from how it is balanced on the bipod.

Might try keeping shoulder pressure constant on the rifle when firing, if the rifle is back heavy due to short barrel and placement of the bipod, you can get vertical, if shoulder pressure is not constant.

Is the rifle jumping at all with the bipod? If the bipod is leaving the ground, that is not good. Try holding the rifle in a more conventional manner with the left hand holding the rifle stock just front of where the recoil lug is.

I can't tell if the bipod is hopping off the ground or not, I may set my camera up and watch in slow motion to see if I can see what's occurring during the recoil. I have just been holding the support under the rear of the stock and pressing back to pull the rifle into my shoulder. I plundered through my ammo stash last night and did find a box of the Federal Gold Match that I got with the rifle and that's shoots really well so next time I get out I'll fire a few of those from the prone position and that'll let me know if it's in my technique from the prone position because I know those loads shot very well through this rifle.

 

[bill123]

If I were you I would do this in 2 stages. Either perfect your prone shooting with factory ammo or work up the load with a shooting position that you are comfortable with. You'll drive yourself nuts if you throw too many unknowns into this.

 

[farout]

I plundered through my ammo stash last night and did find a box of the Federal Gold Match that I got with the rifle and that's shoots really well so next time I get out I'll fire a few of those from the prone position and that'll let me know if it's in my technique from the prone position because I know those loads shot very well through this rifle.

That's the ticket that will get you back on track. When two variables are changed at the same time (shooting position and load) it can be hard to determine cause. Easier to say than do most times.

 

[Derek M.]

Go here: Bugholes from Bipod

and here:

http://www.longrangehunting.com/forums/f116/importance-being-solid-91149/

Then let us know how it's going.

This is the article I read a long time back and is the reason I stopped using the expander. Here's a quote:

I have removed the expander ball on the decapping shaft. Trust me, don't use the expander. In most cases it will just tweak the neck or throw it out of alignment.

Bumping the shoulder .001-.002" is the key to concentricity. If your press is in good shape and you use high-grade dies your end result will be excellent. But, again, get rid of the expander ball. Your brass is fire-formed to your chamber. It is already straight and round--so you dont want to tweak it with the ball.

 

[ltrmc02]

Go here: Bugholes from Bipod

and here:

http://www.longrangehunting.com/forums/f116/importance-being-solid-91149/

Then let us know how it's going.

After reading these articles I'm really thinking that I need a better rear support than the wadded up jackets or pillow that I have been using LOL. That would make sense with most of my spread being vertical. I guess the very little recoil of my 26" heavy 22-250 doesn't show the soft rear support as being much of an issue but with the heavier recoil of the .308 my soft rear support is coming more into play.

I think I'll invest in some nice shooting bags to use for load development and just practice my prone bipod shooting aside from load development.

Thanks guys.