• If you are being asked to change your password, and unsure how to do it, follow these instructions. Click here

Poor accuracy , need help.

I had a custom 300 PRC built that wouldn't shoot smaller than an inch and a half no matter what. I swapped out the scope, scope rings, loaded for it with converted 375 ruger brass. Then when ammo came out, factory ammo, then reloads, then ADG brass, Lapua etc... it just didn't like anything and the best i could do was about 1.5" at 100. The rifle was shoved in the back of my gun safe for years.

I purchased an MPA 300 PRC hybrid hunter and out of the gate it was a 3/4 moa rifle with factory ammo. This summer, while load developing for the MPA and preparing for hunting I stripped some parts from the old 300 PRC, scope, level, rings, bipod...all of the lighter weight parts. While reassembling the original rifle with the heavier parts, I went through and loctited and torqued everything and low and behold...the front screws of the scope rail were finger tight, no loctite, bedded scope rail, all work done by a highly regarded gunsmith.

I also have noted that my MPA shoots in the .5s and high .4s with a brake and eventhough it kicks like a mule, it shoots in the .2s for 3 shots, low .3s for 5 shots in a row...carbon wrapped barrel pushing 245s fast.

My long winded way of saying, check your scope rail, rings, then scope. Then check without a brake, make sure your scope rings are seated forward when torqued. Make sure your action is seated fully rearward when tightening. Tighten in increments, front to rear and make sure the front is fully tightened before the rear.

Lastly, if the rifle isn't adjustable and properly adjusted, you're likely the culprit. You have to be able to mount and drive the rifle repeatabley to know if it's truly the rifle system or you.

With all the years of experience I have, I relegated an expensive custom rifle to the life of a safe queen just because it never crossed my mind to check the scope rail...so stupid, so obvious and simple...but in all the scope swaps and other crap, I never checked the scope rail screws. Check the simple stuff.

Best of luck to you
 
I've been having a similar problem to what you described. I've described it on another forum.

I've tried two different factory loaded ammunition that works well.

12/1/24: edited the next paragraph
You might want to try some factory ammunition to see if there is some hope. I would suggest buying a box of Federal Gold Metal Match or/and Hornady match to see if the gun shoots one of those well.

@Mram10us -- is there something you've experienced when using a brake?
 
Last edited:
I've been having a similar problem to what you described. I've described it on another forum.

I've tried two different factory loaded ammunition that works well.

You might want to try some factory ammunition to see if there is some hope. I would suggest buying a box of Federal Gold Metal Match with the 168 gn SMK bullet AND a box with the 175 gr SMK bullet. Try shooting a group with these two. One of them will likely shoot well.

@Mram10us -- is there something you've experienced when using a brake?
Had a 338 edge that wasn't grouping. Switched from 3 to 4 port brake and touched up the crown. Shot great after.
 
I have a Remington 700 semi heavy barrel rifle in 6.5 Creedmoor sitting in a Magpul stock .
Have you put the action back into the original stock and checked grouping with it?
Or, is this the original stock?
Bedding, trigger fitment, magazine fitment, scope base screws, bottom metal fitment and barrel channel fitment (free floated) can all cause issues singularly or as a combination.
Sounds to me like a simple issue that has been overlooked…

Cheers.
 
Remove and and properly retorque all screws (Action, scope mount bases, rings, picitanny rail screws). Place nail polish/thread locker on them. After that id say bed your rifle. Check barrel clearance between the stock. If none of that works try a different ammo, scope and or shooter in that order. Its all about eliminating variables.
 
I,ve changed 3 scopes and rings on it . The one thats on it now is one that i took off my 338 Lapua Mag and i know that its good .
I did see where you had changed the scopes, but I was asking if you checked the bases ( pic rail) to make sure it is tight
 
It could be a myriad of different things. If you're using Hornady brass, it could be that. If you're brass has been fired too many times and stretched or the necks are work hardened or a donut has formed or it needs to be trimmed, it could be that. The barrel may need a thorough cleaning, not just a little brushing and a few patches. It could be a carbon ring has formed. It could be that the throat has lengthened, and the load is out of tune. If you've changed lots of bullets, powder or primers it could be that. If you've nicked the crown ever so slightly while cleaning, it could be that. If the magazine has a bind with the stock from reassembly or the floor plate wasn't opened when you torqued the screws and the screws aren't torqued equally, it could be that. (I torque to 45 in. lb. on both, front 1st). If the scope base was changed and the front screw is hitting on the barrel threads, it could be that. It could be a bedding issue caused by a number of different things (new stock, bad assembly, over or under torquing, crushing the bedding on one end or the other....etc.).
Other than the loose nut behind the trigger, it could be a multitude of things. Inspect Everything closely and methodically, one thing at a time.
 
Last edited:
I put the brush through it after each trip as i do all my rifles . Usually 3 passes with brush then patch until its clean . I usually only go through 20 rounds max for each rifle each session , (likely less ) but i'll say 20 .
That's not enough cleaning. After the patches come out clean, brush the barrel again with some bore cleaner on it, and I will guarantee you that crud will be coming out. Actually, if you have cleaned it, go do it right now and tell me what happens. Do 10 strokes, in and out counts as 1, with a wet bronze brush and then some patches.
 
I put the brush through it after each trip as i do all my rifles . Usually 3 passes with brush then patch until its clean . I usually only go through 20 rounds max for each rifle each session , (likely less ) but i'll say 20 .
Not to say that this is your issue, but cleaning changes barrel conditions and is definately not necessary after 20 or even 50.rounds. I would cut that out to elimimate variables. Let the barrel get properly fouled, which could take 4 to 6 shots.

Can you better describe your shooting set-up, please. Bipod, bags, rear bag? And are you touching the rifle barrel or scope with your non-trigger hand?
 

Recent Posts

Top