34" 300 win mag

[matthias]

here is the breakdown
i traded for a bat machine 300 win mag with a very heavy 1.75 34" long barrel. it is 30 pounds just receiver and barrel. quite heavy by anyone's standards. it was built as a heavy bench gun and i have aspirations of rebarreling it to 375 chey tac once this barrel is toast. i have an xlr chassis on the way, should be here in two weeks or so. now that that is out of the way here are my questions

- first , has anyone got load data for long barrel 300wm ?
- if the longer barrel is not going to get me some better velocity i think it will be chopped to 26"
- what should my expectations be for the longer barrel be?
- i have used the search function through google and have found lots on the 300 wm but not much with really long barrels.

thanks for your time , matthias

 

[former naval person]

Re: 34" 300 win mag

Using the same charge you'll get about 200 fps more with the long barrel. JMHO

 

[matthias]

Re: 34" 300 win mag

so 200 fps more with 8" more barrel. here is the next question , is 5 extra pounds worth the 200 fps?

 

[Twitch2120]

Re: 34" 300 win mag

plug the numbers in to a calculator and see if the 200 fps is worth the weight to you. if you will shoot 1k+ then maybe. if 600 is your game. chop it to 20" and brake it just to bother people.

 

[MtnCreek]

Re: 34" 300 win mag

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">so 200 fps more with 8" more barrel. here is the next question , is 5 extra pounds worth the 200 fps?</div></div>

I think chopping would save something more like 2lbs, but I could be way off. With a 1.75" barrel, I would just accept it for what it is, a heavy rifle made for the bench.

 

[matthias]

Re: 34" 300 win mag

http://www.onlinemetals.com/calculator.cfm

5.43 pounds for 8 inches

 

[MtnCreek]

Re: 34" 300 win mag

So SS is heavier than granite.

Edit: Thanks for the link.

 

[matthias]

Re: 34" 300 win mag

got me for sure. if i do cut it off i will be sure to weigh it and let you know.

 

[BuzzBoss915]

Re: 34" 300 win mag

That's a lot of barrel which could easily be prone to springing the action unless it's well supported. I'm really puzzled about the motivation? There are other ways to gain 200fps in a .308" bore, just punch it to 30/378 or something like that? I would imagine the barrel harmonics would be all over the place, but maybe that is the reason for the oversize diameter? It's an oddball that is sure to attract attention at the range.
BB

 

[matthias]

Re: 34" 300 win mag

the action is the round 2x10 inch bat. if it gets upset by a 1.75 barrel i would be surprised .

any info on real world long barrel performance?

 

[BuzzBoss915]

Re: 34" 300 win mag

Yeah, well don't be too surprised. It's a 34" lever and I would not be surprised if it sags somewhat, unsupported. There is a reason why there isn't a lot of real world info. Practicality. BB

 

[matthias]

Re: 34" 300 win mag

good point. 34 inches is pretty freaking long. it looks like i will get after it and figure things on my own then post any results that would convince me to keep it long.

 

[jrob300]

Re: 34" 300 win mag

I think this is like the question about 20" 300WM's. Lot's of opinions.... not much data. You're going to have to try it and report back. Very interested in your findings.

John

 

[RyeDaddy]

Re: 34" 300 win mag

Pictures?

 

[matthias]

Re: 34" 300 win mag

no pictures yet, i will however post many of them once my xlr chassis shows up in 1.5 weeks or so. then there will be many

 

[shortround38]

Re: 34" 300 win mag

The only articles I could find on 34" barrels was written by Dan Lilja (Lilja Precision Barrels).

 

[DAVETOOLEY]

Re: 34" 300 win mag

I've been shooting a 2" BAT for 17 years with barrels that big and almost that long. There's no problem hanging that barrel off a 2" BAT. The barrel will sag a bit but not the action. Anyway both are so much over kill you've never prove it one way or the other.

 

[Sparky1950]

Re: 34" 300 win mag

When bullet drag overcomes barrel pressure, velocity falls off. Read Dan Lilja's article here:

http://www.riflebarrels.com/articles/bullets_ballastics/long_barrel_velocity.htm

It gives a good "feel" for the subject.
I have a 338LM 38", barrel length pays off. Also beware that longer barrel equates to more bullet heating due to friction experienced for a longer period of time. Light bullets may disappear due to high RPM and more elastic metals due to heating.
Barrel length has little effect on safe powder charge, since chamber pressure peaks in a millisecond or so and tapers of rather quickly. RPM is directly proportional to MV, so RPM can exceed 250,000 at some twist rates and MV's. Add a little frictional heating, and bullets disappear.
I'd worry more about COAL as pertains to chamber pressure. Bullets jammed into the lands tend to raise pressures.JMHO

 

[RyeDaddy]

Re: 34" 300 win mag

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: matthias</div><div class="ubbcode-body">no pictures yet, i will however post many of them once my xlr chassis shows up in 1.5 weeks or so. then there will be many</div></div>

Thank you, I gotta see this get-up.

 

[matthias]

Re: 34" 300 win mag

I had seen that article at some point before. it is good to see it now with fresh eyes.

glad to hear the action should not sag. i looked at the original bench stock and there is 8" of bedding area under the barrel just in front of the action. so it looks like it was supported in teh old stock.

we are a week out at this point for my xlr !!

 

[matthias]

Re: 34" 300 win mag

I had seen that article at some point before. it is good to see it now with fresh eyes.

glad to hear the action should not sag. i looked at the original bench stock and there is 8" of bedding area under the barrel just in front of the action. so it looks like it was supported in teh old stock.

we are a week out at this point for my xlr !!