Load consistency problems

jmad_81 · Oct 28, 2008

My little bro has been working with his 300 wsm trying to get some 180 ABs to shoot. Went out and shot a .66" three shot group with some mag pro, so we loaded up ten more and couldn't get it to group under three inches!!!!!

Anybody have any ideas as to what might be going on??

I don't think he is flinching because I loaded his gun for him several time while he looked away and some were loaded and some were not. Didn't flinch on the empty ones.

rick smith · Oct 28, 2008

One group doesn't make a load. Been there too many times. May or may not see that group/load again. It could be a loading problem if you were very inconsistant in powder charge/seating depth or used a diferent powder.Rick.

Antelope_Sniper · Oct 28, 2008

I would check my scope mounts, and freefloat to see if something happened to the rifle.

blacktailhunter · Oct 28, 2008

I think we need some more information before we can conclude what problem(s) may exist.

1. has the rifle shot good groups in the past? with what load?
2. is the barrel too clean/dirty?
3. are the mounts, rings and action screws secure(mentioned above)
4. have you done a thorough load work up from starting charge to max
in .5grn increments?
5. is your shooting platform/rest stable and secure?
6. is there any factory ammo that the rifle likes?

The scope could have gone bad. During your next range session, have him shoot another rifle that you know shoots well. If a tack driver shows a shotgun pattern, then you know it is operator error. This is just a few things to cover for now. I'm sure others will have ideas as well.

jmad_81 · Oct 29, 2008

ok Fellas here is some more info...

He free floated the barrel but there is a spot right at the forend that doesn't have the clearence that I would like to see, so it could be rubbing on the barrel.

The only time he has shot this load was the day prior, and it shot three into .66" CTC.

He did clean the barrel before we went out but we shot ten rounds through it and none of them were consistent.

I looked the scope over pretty good and everything looks good, but I'll have him double check the scope and action screws.

We are guilt for not starting at the bottom and working up in .5 gr. increments

. I believe he started at 1-1.5 gr. under max with three different powders(IMR 4350, Mag Pro, Big Game).

The rest is very stable, huge concrete bench with sand bags.

We have tried two different federal ammo and have not had any luck getting it to shoot. It does shoot 150 gr. BT's W/ IMR 4064 at I think 60gr but I'm not sure on the charge weight.
Using Fed GM215M primmers.

I do agree that one group doesn't make a load. It is just really frustrating to have a great shooter one time then a really crappy shooting one next time with the same load. I'll just keep doing battle with it until I win! :twisted:

bullet · Oct 29, 2008

Well, I could be wrong and have been before but it could be the rifle make, along with stock type, load chain (bullet, powder, brass, primer, seating depth). If you would please let me know what rifle you have (make and model, factory or custom). What load chain are you using (see above for example). What scope are you using (scope make, power, objective size, mounts and bases). Please give me this info because I am suspicious of something I have found common to certain make of rifles in 300WSM. I loaded extensively using three different makes of rifles in 300WSM. To me the 300WSM is not as inherently accurate as some have assumed it is on a consistent bases. Thank you for taking the time to answer my above questions, I am truly curious about this in light of my experiences.

Antelope_Sniper · Oct 29, 2008

After checking scope mounts ect, I would certainly eliminate the tight spot between the stock and barrel. I've seen that issue create exactly the condition you are describing in the past.

jmad_81 · Oct 29, 2008

Bullet- The gun is a Remington Stainless SPS. It has a black plastic stock. It is compleatly stock with the exception of free floating and a little lightening on the trigger. The scope is a VXIII B&C 4.5-14x50, and DOES NOT have an adjustable objective. Mounts are two piece luepold. Rings are also luepold. The load is Win. Brass, Fed GM215M primers, 180 gr. AB's, 72, gr. Mag Pro powder, and COAL is 2.86" and is about as long as we can get in the mag.

Thanks for your help!

bullet · Oct 29, 2008

You do know that the synthetic plastic type stock will flex even though the barrel is free floated. I do not think that is the issue. I believe it is the bullet seating and powder. Seat deeper in you powder trials and try something other than Mag Pro for comparison. It might just get down to the fact that your chamber and rifle barrel do not like the 180gr AccuBond. Now take you time and change the above even try a different type and weight of bullet so you can get a fair comparison and can determine if it is the load or the rifle. The 300WSM some times is very finicky especially with bonded and solid copper bullets. Make sure you try the 165 gr AccuBond but also try the 180gr Partition and the 165gr Partition because the 300WSM at times likes the shorter bullet. Your equipment sounds fine I believe it is in your load chain. The 300WSM will take work to prefect it but do not expect minute of angel group after group with bonded or solid copper bullets in a 300WSM that is a factory rifle. Good luck and let us know what happens. I am truly interested in your load results.

blacktailhunter · Oct 29, 2008

Listen to what the rifle is telling you. Forget about the one-time group with the 180 Accubonds. You said it like the 150grn NBT with a different powder. You also said that it did not like another factory load with 180's. My first change would be with the bullet weight. Step down to a 165grn like a Hornady or even the NBT just to see if the rifle tells you something. I own two and know owners of some woderfully accurate factory 300WSMs. After a bullet weight change, I would then go to a powder change. My next move in powder would be to RL-19, but that is just me.

The last thing I would avoid is having too many powder variables at the range. Use all variables with one powder before switching. Some stick powders don't do well after the barrel is fouled with ball powder and vice-versa. To me, Magpro is THE powder for the 270 and 300 WSM, but I have fellow shooters that won't touch it again.

Back up and avoid any short cuts, and I bet you will find a nice load for that rifle.