300 rum Browning max long range 1/8 twist bullet issue

[ramy007]

Hey whats up guys !!

I got gifted by my girlfriend a Browning Xbolt Long range chambered in 300 rum, I mounted it with a vx6 4x24x52 leupold scope with talley picatinny rail and rings. Im having a hard time getting a good group, tried the sirocco 180gr, the eldx 220gr, the corelokt 180gr and neither shoots well, these are all factory amunition, getting groups 2 to 3 inch at 100 yards and 4 to 6 inch at 200yards.

Its after that I realised that the twist rate is 1/8 !!! im not a pro but did some research on the net and saw that an 1/8 twist in a 300 rum i should go 230gr and more.

My last rum was a 1/10 twist remington, so never had to deal with this...

Its not me the problem, ivr been shooting a 300 rum remington 700 for 10 years without a muzzle brake so the caliber dosent scare me, i get good sub moa groups with my 7mm and 30 06.

I looked up the forum and saw that some of you are rocking the 300 win mag and doing well with eld-x 220gr,
and if i do longer bullet they wont even fit in the mag... so stupid by browning, there is exactly 3.65 inch of space in the mag

Being from Montreal, Canada, bullets supply are hard to find so i think im going to have to reload my own bullets which is something new for me or sell the gun and get my girl ****ed at me for a couple of weeks

Did any of you had experience with 300 rum Xbolt max long range ? or do you guys have any tips ?

Thanks !!

 

[762 ULTRAMAGA]

That's frustrating but not uncommon with a factory rifle using factory ammo.
I shoot an 8 twist 30 nosler and it shoots very well with 215 and 220 bergers.
I'm assuming your rifle has a saami freebore but if it's an 8 twist maybe it's throated out a little??
Really tough to say what the issue is with factory ammo, but I'd try to find some 215 bergers.
For a guy that doesn't handload the 300 PRC is the way to go without a doubt.
Good luck

 

[Jwknutson17]

Never understood why manufacturers are going 8 twist. Only makes sense if shooting solids. I've had much better results with 10 twists in my big 30s. 300 norma, nosler, PRC. 9 twist is as fast as I'll go on any custom 30 build too. And it blows my mind that in these big boomers that CIP length mag length isn't used with all the modern long sleek bullets out there these days.

If it were me I would be finding another rifle.

 

[ramy007]

That's frustrating but not uncommon with a factory rifle using factory ammo.
I shoot an 8 twist 30 nosler and it shoots very well with 215 and 220 bergers.
I'm assuming your rifle has a saami freebore but if it's an 8 twist maybe it's throated out a little??
Really tough to say what the issue is with factory ammo, but I'd try to find some 215 bergers.
For a guy that doesn't handload the 300 PRC is the way to go without a doubt.
Good luck

But there 300 prc is an 1/8 twist too and i really like this rifle, i might change but i never shot 300 prc and is the impact at 400 yards as good ?

I hunt moose here and we have 300 to 400 yards shots

 

[ramy007]

Never understood why manufacturers are going 8 twist. Only makes sense if shooting solids. I've had much better results with 10 twists in my big 30s. 300 norma, nosler, PRC. 9 twist is as fast as I'll go on any custom 30 build too. And it blows my mind that in these big boomers that CIP length mag length isn't used with all the modern long sleek bullets out there these days.

If it were me I would be finding another rifle.

Im thinking about it, trust me !!

 

[762 ULTRAMAGA]

But there 300 prc is an 1/8 twist too and i really like this rifle, i might change but i never shot 300 prc and is the impact at 400 yards as good ?

I hunt moose here and we have 300 to 400 yards shots

Theres absolutely nothing wrong with an 8 twist for 212 grain on up.
I had a friend with a CA 300 prc 8 twist and the factory 212 eldx shoot really good.
The prc is a fantastic choice for moose well beyond 400 yards

 

[Gila]

Browning has a 1:10” twist on the ABLRH 300 rum. So, unless it is a custom barrel, you have a 1:10” twist in your rifle. I don’t see how a custom barrel maker would want to twist a 300 RUM barrel faster than 1:9. Also, factory production rifles are built to SAAMI COAL...So is all factory ammunition.

I have a 300 win mag with a 1:10” and it will stabilize anything. I went with AICS bottom metal so I could play around with seating depth some day. The longest AICS mag that will fit my action is 3.715”. You can get a longer AICS magazine to fit your RUM. There is a lot of case capacity there in your RUM and a lot of chamber pressure to deal with. If you want to roll your own and play around with seating depth, i would give the reloading folks a shout.

To state the obvious, a thousand and one things could go wrong with a new rifle that shoots loose groups. I would eliminate the optic and the rings, mounts, base before doing anything with the rifle itself. Then If the problem persists I would call Browning customer service for advice.

EDit: I was looking at the A-bolt specs....the x-bolt does show 1:8” barrel twist. I think it may be a misprint as that is really fast for a RUM.

 

[Southernhunters]

OP.....look on the barrel next to where it list the caliber and it should tell you the twist rate so you can confirm....


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[260madman]

XBolt Longrange Max have an 8” twist. OP must not have liked the answers he received over at LRH. Some of the replies were pretty

 

[SDHNTR]

Shoot monos. You can’t out twist em.

 

[762 ULTRAMAGA]

There's a lot of assumptions being made about an 8 twist being too fast..
Call Hornady and talk to their techs about it, they've done a lot of testing with 225 eldms and Atips in 8 twist barrels with really good results.
10 twist barrels are pretty marginal with long high bc bullets, especially in colder weather.
I would never own a long range 30 cal with anything slower than a 9 twist barrel

 

[Gila]

Hornady, Nosler, Berger all list 1:10” as a recommended minimum for their heaviest bullets. The only exception to this is Berger recommends 1:9 for their 245 EOL bullet. It is possible to over twist or every barrel would have the same twist regardless of cartridge. If any cartridge is susceptible to over-twist the 300 RUM is certainly one of them. JOMHO.

 

[WeiserBucks]

There's a lot of assumptions being made about an 8 twist being too fast..
Call Hornady and talk to their techs about it, they've done a lot of testing with 225 eldms and Atips in 8 twist barrels with really good results.
10 twist barrels are pretty marginal with long high bc bullets, especially in colder weather.
I would never own a long range 30 cal with anything slower than a 9 twist barrel

While you're on the phone with them, ask them why the competition ELR shooters are having their 8 twisted A-Tips go up in smoke once the barrels have a few hundred rounds on them? It's the same reason that the Army gave up on the 300 Norma, because they were contracted with 8 twist barrels and the bullets started to come apart once the barrels had some wear on them. 8 twist is to fast for cup and core bullets over the life of the barrel.

Many brand new 8 twist barrels shoot great and the owners are happy, once the throat starts to crack and wear the bullets cant handle it. I've seen upwards of 20% of bullets fail to reach the target out of one rifle in particular at a recent shoot I attended, heavy cup and core bullets out of an 8 twist with 500+ rounds on it.

 

[762 ULTRAMAGA]

While you're on the phone with them, ask them why the competition ELR shooters are having their 8 twisted A-Tips go up in smoke once the barrels have a few hundred rounds on them? It's the same reason that the Army gave up on the 300 Norma, because they were contracted with 8 twist barrels and the bullets started to come apart once the barrels had some wear on them. 8 twist is to fast for cup and core bullets over the life of the barrel.

Many brand new 8 twist barrels shoot great and the owners are happy, once the throat starts to crack and wear the bullets cant handle it. I've seen upwards of 20% of bullets fail to reach the target out of one rifle in particular at a recent shoot I attended, heavy cup and core bullets out of an 8 twist with 500+ rounds on it.

Funny you mentioned the 300 NM
I ran one in the past with an 8 twist and shot 215’s exclusively.
It shot exceptionally well until approx 800 rounds (which is about the average barrel life of the NM), guys are pushing 300 prcs really hard and getting about the same barrel life with slower twist barrels.
I'm on my 3rd 8 twist big 30 cal barrel and I haven't had any weird failures that you're talking about, I mainly shoot Bergers.
If you want to talk about Hornady bullets going poof then check out the issues with 180 eldms from 8 twist 7mms.
Don't blame it on over twist cuz that's not the issue

 

[Flyjunky]

Funny you mentioned the 300 NM
I ran one in the past with an 8 twist and shot 215’s exclusively.
It shot exceptionally well until approx 800 rounds (which is about the average barrel life of the NM), guys are pushing 300 prcs really hard and getting about the same barrel life with slower twist barrels.
I'm on my 3rd 8 twist big 30 cal barrel and I haven't had any weird failures that you're talking about, I mainly shoot Bergers.
If you want to talk about Hornady bullets going poof then check out the issues with 180 eldms from 8 twist 7mms.
Don't blame it on over twist cuz that's not the issue

I've also heard that number of grooves has a big affect also. I remember Broz talking specifically about how bad 4 groove barrels inscribe the jacket compared to 5+ groove barrels and how that has a lot to do with bullets blowing up.

I'm shooting an 8 groove 300wm right now and it's a very accurate rifle, probably getting around 400+ rounds right now. I'm running it pretty hot with RL26 and Berger 215's, no problems so far. I believe, as well, it has more to do with the bullets than it is the 8 twist.

 

[762 ULTRAMAGA]

I've also heard that number of grooves has a big affect also. I remember Broz talking specifically about how bad 4 groove barrels inscribe the jacket compared to 5+ groove barrels and how that has a lot to do with bullets blowing up.

I'm shooting an 8 groove 300wm right now and it's a very accurate rifle, probably getting around 400+ rounds right now. I'm running it pretty hot with RL26 and Berger 215's, no problems so far. I believe, as well, it has more to do with the bullets than it is the 8 twist.

Yes I agree
I think 9 twist is about perfect for most 30s but an 8 as absolutely great with 212 on up.
I'm no expert but going with my personal experience, and the insight from experts, there are many factors that lead to bullet failure and the number one is fire cracking/ erosion.
Once a barrel has those issues it doesn't matter if it's an 8 or 10 twist, you're gonna have problems.

 

[WeiserBucks]

Yes I agree
I think 9 twist is about perfect for most 30s but an 8 as absolutely great with 212 on up.
I'm no expert but going with my personal experience, and the insight from experts, there are many factors that lead to bullet failure and the number one is fire cracking/ erosion.
Once a barrel has those issues it doesn't matter if it's an 8 or 10 twist, you're gonna have problems.

I tend to agree, though it seems like certain bullets have more issues with fast twist and worn barrels.

Looking at you Hornady!

 

[762 ULTRAMAGA]

I tend to agree, though it seems like certain bullets have more issues with fast twist and worn barrels.

Looking at you Hornady!

For sure
Eldms and A tips have very thin jackets compared to Bergers
Pretty sure the eldx would hold up better too since they're jackets are pretty thick

 

[gribble21]

I'm running the same rifle with handload 220 eldx's and it's shooting great with IMR 8133 (2830 FPS) it's a little slower then I wanted but the RL26 (3150 FPS) had it way to hot.

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