Barrel chop for suppressor on 300WM - blaser specific plz

[Datchew]

I request info, guidance, or experience specifically as regards blaser barrels please.
I won't cry (much) if you have some good info relevant to the situation on non-blaser barrels but as it's a bit of an oddball twist barrel, that's really my focus.

This is pertaining to a 300WM standard barrel with a 1:13 twist at 25.5" from the factory.
Bullets will be in the 168-200grain range. 168-180 for monos, 180-200's for cup & core (A-frames.)
Prefer to stay north of 2900 FPS for velocity with the end result.

I'm quite happy with my load development and have tested them on large Texas piggies for penetration and non-disintegration in prep for plains game.
Grouping is repeatable hot or cold barrel and sub-moa. Frankly, the blaser makes handload tuning a little silly. It just shoots everything well.
Velocities range from 2950-3150 FPS.

The can will be TBAC ultra 7.

I'm well aware of the velocity losses and potential gains with shortening the barrel and putting a can on.
I'm not likely to ever hunt outside of 500-700m, even if I go on a backpack mountain goat hunt. Legs still work.

For assumptions sake, I'm looking at approximately -36 FPS/inch loss for length reduction.
This puts me targeting 21-22" minimum for the barrel.

I know this is a lot of info and in the real world, I'll be chasing consistent grouping and accuracy and not expecting the critters to detect the delta in velocity inputs to their innards. This is hunting, not sniping.

My real interest is whether or not there's something esoteric I need to take into account with the blaser barrel, the non-standard twist rate, or generally any surprises that it would be polite to warn me about before we start a bit of choppy chop chop.

Thanks much.

 

[Hogpatrol]

The question I would have is, what effect will the loss of velocity have on bullet stability in a 13 twist?

 

[Datchew]

The question I would have is, what effect will the loss of velocity have on bullet stability in a 13 twist?

Excellent question.

 

[BeeMaa]

@Datchew - Did you special order your Blaser barrel to have a 1:13" twist rate? Are you absolutely positive that it's 1:13 and not 1:11?

The reason I ask is because I have two Blaser 300WM barrels and they are both 1:11". I also contacted Euro Optic who said the standard twist rate is 1:11. Might want to double check.

As for cutting and threading, I know that Blaser USA will thread your barrel. I believe there is a specific process they use to do so. You should inquire at your local dealer to see if they will oblige you and maybe even cut it to the length you want.

Not sure about the losses in velocity or any of that. One of my 300WM barrels came threaded from the factory and I have 22lr barrel that's also threaded.

You should also take a close look at a bullet stability calculator. Both of my 300WM's shoot lights out with 165 grain Barnes TTSX.

 

[Datchew]

Really appreciate your note BeeMaa.

I will check again. Would be VERY happy to have written it down wrong and have a 1:11".
Nothing custom in my barrel.

Yes and thanks. I can actually drop my barrel locally at blaser USA here in San Antonio for threading and sights.

My stick is putting 168 ttsx in 0.767" groups over 69 gr of H4350 at avg velocity of 3030 FPS.
Pigs love it.

I have room to add velocity and adjust seating but I'll do that after threading on the can as a final tweak.

 

[Red Leg]

Curious why put a suppressor on a 300 Win Mag? That particular chambering benefits from a bit of barrel length which the R8 delivers with its short action.

 

[Daisy]

Cut and thread it. You’ll be happy you did.

 

[BeeMaa]

I know cutting the barrel will reduce bullet velocity, and I also know that adding a suppressor will reduce the velocity as well.

You may want to keep the barrel length and add the suppressor to see where you land. Always easier to cut it shorter. Much more difficult to add length without adding a new barrel.

IMO - Suppressors are great for stationary hunts from a blind or hide where there's not much moving around. Culling from a fixed position (sniping) and predator hunting come to mind as good applications for a suppressor. If I am doing any stalking, the added weight becomes a burden as well as throwing off the handling of the rifle. I prefer the weight to be between the hands, not out at the end of the barrel.

 

[UpNorthMI]

I contacted my Blaser dealer, Cove Creek about either buying or having Blaser barrels threaded, they told me no threaded barrels from Blaser come into the US and that all barrels they get threaded go to Mag-Na-Port in Michigan for the work. I have 2 .308 Blaser barrels currently being threaded by Mag-Na-Port. Apparently the Blaser warranty remains in place if the work is done by Mag-Na-Port.

Why chop the barrel, just use an over the barrel type suppressor to limit length extending beyond the end of the barrel?

 

[AimSmall]

x2 on standard Blaser twist being 1-11" in 30 cal.

Note the 190-200 gr monos want a 1-10".

168ttsx, 180ttsx, 175lrx all shoot lights out in the R8. I have great luck with 100V powder in 300wm.

While I personally do not use a suppressed, shortened barrel on the 300wm, (as it is only fired once, maybe twice, while hunting) I use them on others, suppressed, with good results.

 

[Daisy]

I know cutting the barrel will reduce bullet velocity, and I also know that adding a suppressor will reduce the velocity as well.

You may want to keep the barrel length and add the suppressor to see where you land. Always easier to cut it shorter. Much more difficult to add length without adding a new barrel.

IMO - Suppressors are great for stationary hunts from a blind or hide where there's not much moving around. Culling from a fixed position (sniping) and predator hunting come to mind as good applications for a suppressor. If I am doing any stalking, the added weight becomes a burden as well as throwing off the handling of the rifle. I prefer the weight to be between the hands, not out at the end of the barrel.

Suppressors almost always add velocity Bee. They act as a “pseudo” barrel, allowing pressure and burn to continue longer. I generally gain about 25fps when adding a can.

 

[Hogpatrol]

Original design was for a 1-11 twist, 24" barrel. As above, shooting the heavy end of the range, 1-10 twist. In another magnum, I've shot the heavies in a 9.5 and a 9, accurate at extended ranges.

 

[BeeMaa]

Suppressors almost always add velocity Bee. They act as a “pseudo” barrel, allowing pressure and burn to continue longer. I generally gain about 25fps when adding a can.

You are correct in come cases but it can go either way. Depends on the load, bullet, caliber...etc.

Either way, I would expect a change in POI vs not using a suppressor.

 

[Datchew]

Either way, I would expect a change in POI vs not using a suppressor.

I do indeed expect such.
Some say they don't get much change but i plan to finalize load development after adding the can and make it a permanent resident on the barrel

 

[Datchew]

Found my notes and indeed, my handwriting is horrible.
It's like the handwriting of a surgeon with late stage arthritis and hand tremors.

Anyway, it's 1:11.
The twists aren't in the blaser website barrel matrix chart but there's one you can find if you search for blaserpro twist rates as this site isn't link friendly.

Thanks much for catching that.

 

[Daggaboy375]

+1 on my suppressors increasing velocity.


DB

 

[Daisy]

Found my notes and indeed, my handwriting is horrible.
It's like the handwriting of a surgeon with late stage arthritis and hand tremors.

Anyway, it's 1:11.
The twists aren't in the blaser website barrel matrix chart but there's one you can find if you search for blaserpro twist rates as this site isn't link friendly.

Thanks much for catching that.

If you plan on using this in a shooting house, a suppressor is the only way to go. That caliber and larger for Whitetail deer from a stationary blind it’s just too concussive without one.

 

[NJC]

Have you called thunderbeast directly? I think they have other options that would not require you to chop the barrel.

I’m actually dropping off my r8 300wm barrel to them the next time I have a clear afternoon.

 

[Daggaboy375]

My suppressors are Form 1.

Big and heavy steel. Not for stalking.

Movie quiet with 22 LR from a deer blind
on squirrels.

Threaded R8's in 6.5 Man Bun and 375 H&H.

DB

 

[Daisy]

Look also into over the barrel/reflex suppressors. AB raptor comes to mind. Can have as short as 4” of length added to barrel with suppressor on, so might not need to remove much barrel length when threading.