Gunsmithing Built 300 WM not performing **UPDATE**

[nortac]

Ok, I have a custom built 300WM that I am needing some help with and willing to send it to a competent smith to look at and tune if they think they can help.

The rifle:

Remington 700 LA trued
Rock Creek 26" barrel
1/10 twist
Threaded 5/8x24 for suppressor and brake
New PTG minimum SAMMI spec reamer used.
Holland recoil lug
Holland brake (I love this brake!)
Manners stock with mini chassis and bedded to action.
20 MOA Seekins base
Nightforce 5-22x50
TPS rings


The gun simply does not shoot well. I had it built to use 208 A-Max bullets seated at 3.60 right at the lands. Load development was based on H1000 and H4350. H1000 throughout the load data averaged about 1.75 to 2.5 inches at 100 yards. H4350 averaged about 1.25 to 1.75 inches. (5 shot groups). Yes, I could try other powders but so far the results have said why bother.

The rifle has very modest recoil and is not very loud based on the brake. Personally, I think the brake is not trued up properly or something is up with the barrel.

Anyway, I have a lot of money tied up in the rifle and just wanting to figure out what I need to do to get it shooting. My expectation is average 5 shot groups around .5 to .75.

 

[Mgordon]

Re: Built 300 WM not performing

I know that you do not want to deal with the original builder of the rifle for various reasons, but it is the correct way to approach this situation. If you call other builders, most would tell you it should go back to the original builder first not only to let them make it right, but also because they are already familiar with your rifle.

I understand how it can be frustrating paying a lot of money for a project that is not correct, but that should be the first coarse of action.

Mark

 

[LRI]

Re: Built 300 WM not performing

Quit seating your bullets at the lands.

Imagine a cough and a sneeze. Which is more violent? The sneeze right?

You want your gun to "cough" a bullet down the barrel. Jamming a bullet (in this case a big, heavy bullet with lots of grunt (powder) next to/into the lands invites uneven pressures and other goofy chit. It "sneezes" the bullet.

Back it off .02" and see what it does. Watch it on a chronograph if you can. I'd bet your STD deviation drops which is never a bad thing.

Try it and see what it does. Your "lemon" just might turn into a glass of CountryTime.

Good luck.

C.


Worse comes to worse, we'll be happy to look at it. Headed to the range today to test a new one, but will be in the shop for part of the morning.

 

[MikeeBooshay]

Re: Built 300 WM not performing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">Quit seating your bullets at the lands.

</div></div>

This was my experience with a short throated (min SAMMI also )300 WM. Stiller TAC 30, Rock barrel, AICS. Anything I put in it that got close to the lands shot not so good. Getting .050 jump even though it results in a lot of bullet in the case made it shoot bugholes, no other changes made. Don't know about others experience with 208 AMAX, but that was mine. Applied to 190 and 240 SMK also, in the same rifle.

Side benefit, unplanned, was the easy feeding with a shorter round.

Trying taking ten of your rounds, and reseat the bullets .050 deeper. Costs nothing and you might like it.

 

[Papagrizzly]

Re: Built 300 WM not performing

Try some Berger 210gr bullets as well as H4831SC powder, weighed very evenly. If that doesn't shoot, take it back to the Smith.

By the way, your .5 MOA expectation on a custom rifle is very reasonable, and easy to achieve. However, its not always the gun. Often its the ammo, and sometimes the shooter.

 

[300sniper]

Re: Built 300 WM not performing

my first question for someone saying that their new rifle doesn't shoot good is "are you a capable shooter?" i don't know the op so i mean no offense but are you capable of shooting a win mag 1/2 moa? of course everyone on al gore's internet is but in real life, some people just aren't 1/2 moa shooters.

 

[ackleyfan]

Re: Built 300 WM not performing

Take the brake off and shoot it, to see if there is a change!

 

[kraigWY]

Re: Built 300 WM not performing

Another ideal. Switch bullets and see what happens. My 1000 yard match rifle in 300 WM likes 200 Gn SMKs. I tried heavier, I tried Ligher, Nope, it wants the 200 SMKs. Don't matter what powder, still wants the 200s. (Thought it likes 4350 the best).

Also I don't load mine to the lands. Don't know if it would make a difference on my rifle because I never tried it. When I first built it and started loading for it, I was also loading 300 WMs for some of our other guard rifles so I made them all the same OAL Sierra called for.

Not saying your rifle will only shoot 200s (or anything else) or not but it would be worth looking into

 

[raptor99]

Re: Built 300 WM not performing

Sounds like you need to expermint with different bullets and loads. It can make a world of difference. Also take the brake off it and try it that way once..But 300WM are not plesant to shoot off a bench so keep that in mind.

 

[2156SMK]

Re: Built 300 WM not performing

Nobody mentioned this yet, but try it at 200 and 300yds.
You might be suprised to find the groups are the same size or even smaller than they are at 100yds.
Those heavy long bullets won't "go to sleep" until after 100yds when driven as fast as the 300 will drive them.

Just something to try...
I have seen 338 lap mag shooters with the same complaint and they were suprised as hell to see smaller groups at 200yds than they were getting at 100yds.

 

[nortac]

Re: Built 300 WM not performing

Thank you all for the replies. I will try a few of the suggestions one last time before I talk to one of ya'll about taking a look at the gun. I have talked to the smith that built it and he didn't have a clue. He has built other guns for me and I haven't had any issues. I have decided to move on from him so further contact regarding this rifle would be futile.

To keep it simple, yes I am a capable shooter. I do not have any guns that shoot this bad. Including all my semi autos. Hell my Sako and Weatherby hunting guns will print sub MOA all day long.

I will try seating back some, without the brake (actually a good idea I planed on doing but got so frustrated I kinda gave up), 200 and 300 yards...Im really wanting to stick with the 208's as I have around 500 of them.

Thanks and I will keep ya'll posted

 

[mdmp5]

Re: Built 300 WM not performing

nortac, before you waste any more ammo trying to tune a load, hear me out. There is absolutely no load you can press that is going to shoot to your liking out of that rifle. 2" at 100 yds signifies a problem with the rifle, not the ammo. First thing you want to do is check your optics platform; check to be sure that the base is snug, and that the rings are snug. Trust me, I have shot many rounds thru a rifle, perplexed as to why it was grouping terribly, only to figure out that the base had come loose. If that is ruled out, check your action screws, and make sure they are torqued correctly to the stock. If that isn't it, try shooting the rifle without the brake. I know it is gonna sting, but it has to be done. If still no joy, unfortunately you will have to send the rifle in. Hopefully it isn't the barrel.

 

[nortac]

Re: Built 300 WM not performing

I have checked everything out as far as the gun and scope. I have checked double checked and triple checked all the screws on the entire gun. I have replaced the original 3-15 Nightforce with a Leupold then to a new 5-22 Nightforce.

I have not shot it without the brake though and I will do that along with a few other things prior to sending the gun anywhere.

Thanks!

 

[Kells81]

Re: Built 300 WM not performing

The Kimber 300wm AT I had was real finnicky even after getting it pillar bedded by triple g in stephenville. Try different bullets ie Berger vld's. If you need some and are close to granbury can swing a few to you.

 

[Rprecision]

Re: Built 300 WM not performing

Take a look at the basics, bedding, crown, optics, mounts, Etc. Make sure nothing is toughting the barrel from final assembly, Etc.

I would take all the variables out of it. Bullets, loads, etc.

Does the brass look, ok?

 

[TxShooter63]

Re: Built 300 WM not performing

Try 2.40.... If it helps I use amax 208's with 78gr of H1000 with an overall length of 2.40 which yields 2810fps through a suppressor with about 10 fps ES.

 

[TxShooter63]

Re: Built 300 WM not performing

You might try buying a box of black hills or FGMM and see how it does with that. If it won't shoot either of those under 1" you have something wrong....

 

[mdmp5]

Re: Built 300 WM not performing

Like I said above, I will lay 10 to 1 that no load or bullet will change the outcome. A good rifle will shoot military surplus crap well below 2 moa at 100 yds. Changing bullets is a waste of time in this case

 

[nortac]

Re: Built 300 WM not performing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: palmik</div><div class="ubbcode-body">Like I said above, I will lay 10 to 1 that no load or bullet will change the outcome. A good rifle will shoot military surplus crap well below 2 moa at 100 yds. Changing bullets is a waste of time in this case </div></div>

I agree with you on this!

The variables have been taken out of the equation as far as the general mechanics of the gun. I am still going to try a few things with my load and take the muzzle brake off to see what it will do.

Thanks again everyone

 

[cfish36]

Re: Built 300 WM not performing

I understand what palmik said. 1 thing that I have noticed with 208's in my .300 WM is that they are extremely sensitive to seating depth(by that I mean distance off the lands). Mine do not like to be touching the lands but at the same time they don't like to jump either. I seat mine to .015" off the lands.

Now, you have to realize that as you shoot, your throat will erode a little bit. Which means you need to constantly check.

I love the way my 208's shoot but I am looking for other bullets that are less sensitive without giving up BC.

Keep in mind that I am not an expert by any stretch of the term. This is just what I have learned (with the help of other shooters).

 

[Willys46]

Re: Built 300 WM not performing

I guess I would disagree with switching bullets will not help, And trust me I understand you have 500 sitting there. I built a 6 x47 to shoot the 115 DTAC's, bought 500 and they shot horribly (1.5)! Tried the 105 Bergers and it shot .153 for five shoots!

Life too short to try and get them to shoot, so I bought more 105's.

 

[ZLBubba]

Re: Built 300 WM not performing

PM sent

 

[cfish36]

Re: Built 300 WM not performing

I agree with willys46; some barrels just don't shoot certain bullets. However if your barrel was made specifically to shoot the 208's than I don't know what to say other than THAT SUCKS.

I had a 7stw that would not shoot any bullet that weighed over 160 grains, so I went with 160 accubonds. But once again I did not have the barrel chambered for a certain bullet profile.

I have a mcgowen barrel 1 in 10 twist and it shoots 208's just fine. The action is not trued, so by fine I mean 1 moa(i don't expect more until I get the action work done).

I definetly noticed a huge improvement by jumping only .015" as opposed to .045". the chamber is deep so I have to single feed, but changing my seating depth gave me the best groups I have ever shot with this rifle.

I would have to say that it sounds like a rifle issue. If there is some close by that knows guns I would have them look at it.

Sorry to hear that you are having troubles. I know what its like to have a rifle that doesn't shoot. VERY FRUSTRATING. Hang in there; there has to be a reasonable explanation.

 

[Sage Flats Shooter]

Re: Built 300 WM not performing

I dealt with a Rem 700 tactical in 300 WM this summer which had a similar problem. The magazine was huge and the throat was long so I long seated the bullets so that they were just off the lands. Several test loads later the best it would shoot is 1.5 to 2" groups. I grabbed a cheap box of factory which were nowhere near the lands and I shot a 5 shot group outside to outside sub 1" with 4 of 5 almost touching. Just my $.02 and much as I hate to say it sometimes you can just get a bad barrel.

Steve D. the HP
Sage Flats Shooter

 

[nortac]

Re: Built 300 WM not performing

Update -

Okay, I finally had a chance to get out yesterday and try a few new things. I think I will need another round of shooting but I did get some results.

I bought a box of Federal 180 grain off the shelf ammo as a control

I loaded 9 rounds of 208 A-max with H4350 at 67.5 grains (this grouped the best in my original testing with this powder) at 3.55OAL (The bullet hits the lands around 3.60)

I loaded 9 rounds of 208 A-Max with H1000 at 77.0 grains (this grouped the best in my original testing with this powder) at 3.55OAL

My mistake was only loading 9 rounds each. Should have loaded 20 rounds each but as a test I was just shooting 3 round groups.

Anyway here are the results

1. First group with the Fed 180's as a control without the Muzzle Brake.
Five (5) shots measured 1.565

2. Fed 180's WITH BRAKE
Five (5) shots measured 1.004

3. H4350 (velocity with this load runs 2823)
Three (3) shots measured .542 without Brake

4. H4350
Three (3) shots measured .537 without Brake

5. H4350 (WITH BRAKE)
Three (3) shots measured .873 with Brake

6. H1000 (velocity with this load runs 2828)
Three (3) Shots measured 1.496 without Brake

7. H1000
Three (3) shots measured 1.640 without Brake

8. H1000 WITH BRAKE
Three (3) shots measured .914 with Brake

I had inconsistent results with the brake on and off.

H1000 obviously sucks major balls in this gun!

Factory Fed 180's shot about what I would expect from a general hunting gun, although this was not built as a general hunting gun.

H4350 was very close to my expectations as a 1/2" gun but only without the Brake. More testing needed.

Conclusion -
I need to spend some time doing five (5) shot groups with the H4350 with and without the brake.
There seems to be indication that the muzzle brake installation might have been done improperly.
Never, never, ever again will I use H1000 in this gun.

Any thoughts?

 

[RingingSteel]

Re: Built 300 WM not performing

The brake can change the harmonics of the barrel. One of our shooters added a brake to a sub-1/2MOA gun and his groups opened up drastically. Drove him nuts trying to make his go to load work. All he did was adjust the charge and the gun went back to its tiny little bug holes. In his case I think he increased his charge. What I do know for sure after a little load development and the addition of a brake we are going to have to bring our A game to keep up with him.

 

[Tactical Support]

Re: Built 300 WM not performing

I never got the 208 AMAX bullets to shoot well in my 300WM. I gave up and used Sierra 210 SMK's and H1000. Bug holes from there on.

 

[c3006]

Re: Built 300 WM not performing

Just wondering how hard the bolt was to close on the factory Amo you tried?

 

[nortac]

Re: Built 300 WM not performing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RingingSteel</div><div class="ubbcode-body">The brake can change the harmonics of the barrel. One of our shooters added a brake to a sub-1/2MOA gun and his groups opened up drastically. Drove him nuts trying to make his go to load work. All he did was adjust the charge and the gun went back to its tiny little bug holes. In his case I think he increased his charge. What I do know for sure after a little load development and the addition of a brake we are going to have to bring our A game to keep up with him. </div></div>

I have been up and down the powder scale with both H1000 and H4350 with the brake on and it did not perform very well. I did see an improvement with H4350 though without the brake. I still need to test that a bit more though.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: c3006</div><div class="ubbcode-body">Just wondering how hard the bolt was to close on the factory Amo you tried?</div></div>


No issues feeding the factory stuff.

 

[Chabrone]

Re: Built 300 WM not performing

Maybe try backing your OAL back to 3.50 or 3.45, all my guns with 208's like a little jump.

 

[nortac]

Re: Built 300 WM not performing

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Chabrone</div><div class="ubbcode-body">Maybe try backing your OAL back to 3.50 or 3.45, all my guns with 208's like a little jump. </div></div>

I pulled back to 3.55 and I figured that was a pretty good jump from there to 3.60. I'm not sure 3.5 or 3.45 would make much difference.

Thanks for all the responses.

 

[stockdoc]

Re: Built 300 WM not performing

I competed with a 300 for a few years using RL-22 powder. Granted that was using 190 smk, but that gave me the most consistency and accuracy of all the other powders. It is also very slow burning and will give you great barrel life

Got around 3k barrel life. In comparison, a friend of mine shot out his barrel in about 1100 rounds. We both had Hart 1 in 10 twist barrels in max Hv contour. Fwiw

 

[jagged77]

Re: Built 300 WM not performing

I've got a factory R700 .300WM which has always been around 3/4 - 1 MOA with 200 and 220 SMK's. When I got hold of some A-max 208's I loaded them close to the lands and got poor results. After about 200 wasted A-max's I moved away from my usual powders (RE22 / H4831) and went with VV N165, loaded to AI mag length (miles off the lands) and suddenly found the holy grail. Not sure if it was the jump or change to N165 that solved the problem.

 

[nortac]

Re: Built 300 WM not performing

Latest update 2/26

Gun is good to go. Only thing I can think of is the 208 either suck ass in my gun or 100 yards is not far enough to get them stabilized.

I loaded up some 190 SMK with H4350 and IMR 4831. H4350 did very well with the 190 SMK's and averaged less than .500 5 shot groups. I did subtract one pulled shot though.

H4350
OAL 3.450
Group 1 .299
Group 2 .606 (5) shots .235 (4) shots
Group 3 .879 With pulled shot .408 (4) shots
Group 4 .386

IMR4831
Group 1 .392
Group 2 OPENED WAY UP - Not sure what happened
Group 3 .474

I am pretty satisfied with this and plan to do some more work with the 190's and maybe some 210 Bergers. I might get back to the 208's but not anytime soon. I was very frustrated by them.

Thanks for all the help and input!

 

[beretta989]

Re: Built 300 WM not performing

Hmmm my TRG shot in the .3s with the 208's with H-1000. Glad you got it all figured out now.

 

[Jayman_10X]

Re: Built 300 WM not performing

Nortac,

Glad to see you got it sorted out. Sorry it took so much hearache to get there. My brother is experiencing a somewhat similar issue with his 260 Rem - a recent build by a well reputed riflemaker. We're still not sure what's wrong, but no matter what bullet he uses, powder, etc. His first two groups at 100 yds are money - .1 to .2 MOA without fail. From there on the they open up. It's like the barrel is fouling too much.... Just doesn't make sense....


thanks
Jason

 

[ProImaging]

Re: Built 300 WM not performing

god to hear, im working on my 300wm trying to figure out what load it likes. the 200 is the best so far. didnt like 185's, 208's or 210's

 

[Hookturnr]

Re: Built 300 WM not performing

I had a similar experience with one of my RUMS, it would NOT shoot the 208 AMAX but absolutely loved the 200 NAB to the point of group sizes I won't mention 'cos no one would believe it without being there. I did find both the RUMs like about .020 jump with both bullets though which was helpful in that I kept to mag length doing it. I've had good luck with bergers at .045 jump as well. Right on or near the lands isn't always the answer in my experience.