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New 338 WM-Do I have a Slow Barrel?
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I have two 338 WMs. An older Browning A-bolt with a 26 inch barrel and a new Weatherby Vanguard SUBMOA with a 24 inch tube. I went to the range today to shoot em both using my pet load for the Browning. It's nothin cosmic, just the max load listed in the Barnes reloading manual consisting of 67.5 grains of IMR 4350 propelling a 225 grain Barnes X-bullet not the TSX,TTSX, or MRX.

I chronographed these loads through both rifles and the Browning turned out the same average velocity it has for several years...2818 fps. The Weatherby with its shorter 24 inch tube turned out an average velocity of 2689 fps. That's a difference of 129 fps. Is this typical performance for a 338 WM with a 24 inch tube or do I have a "slow barrel" in my new Weatherby? Any info will be greatly appreciated.
 
Posts: 452 | Location: North Pole, Alaska | Registered: 28 April 2001Reply With Quote
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For what it is worth, QuickLoad puts the 26" tube @ 2887 fps and the shorter 24" tube @ 2840 fps. So clearly the 'theoretical' difference is much less than you have observed.



 
Posts: 160 | Location: Southern California | Registered: 28 September 2000Reply With Quote
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In the loading guidelines I got with Barnes 30 cal 168gr bullets they mention reduced bearing surface,lower pressure may have to exceed max load to achieve max velocity by one or two grains work up 1/2 gr increments.

I work up load for the 300WSM and 280AI later I switched over to TSX bullets in the 300WSM I had to increase powder the 280AI was OK. The shorter barrel is going to effect the velocity some. Well good luck


VFW
 
Posts: 1098 | Location: usa | Registered: 16 March 2001Reply With Quote
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It could be a change in powder lots, length of throat in the barrel, or any number of things. I have seen the same box of ammo vary by over 200 fps on the same day in two different rifles. Since it is a new rifle, you will likely have to change your load to suit it. Nothing unusual about that.


A shot not taken is always a miss
 
Posts: 2788 | Location: gallatin, mo usa | Registered: 10 March 2001Reply With Quote
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Interesting enough ...I shot my Wthby 338-06 with 225 grain Sierra SPBT,and IMR 4350 at 60 grains....supposed to go app 2600.FPS,thru the crono at almost 2800 FPS (just a tad under) ....I also shot some 185 & 210 Barnes TSX a 100 yards the groups were about the same as the sierras ???? BB34
 
Posts: 126 | Location: Vermont | Registered: 16 February 2008Reply With Quote
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Thanks for the replies. I'll be headin back to the range next weekend so hopefully things will improve.
 
Posts: 452 | Location: North Pole, Alaska | Registered: 28 April 2001Reply With Quote
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quote:
Any info will be greatly appreciated.



OK-here goes: According to Bob Hagel, with whom I tend to agree, "All rifles are idividuals. What may prove to be a maximum load in one may be quite mild in another, and vice-versa."!!

So, when it works out that you get identical velocity performance in one of your own rifles from a load shown in a reloading manual, it is JUST a happy (or otherwise) coincidence.

Your rifle is just as likely to do something more or something less than what the reloading manual shows.

Your second rifle shows exactly this phenomenon here. It could have given a HIGHER velocity than the 26" one (not as likely, due to being shorter, but possible!!)

Now, is your 24" barrel slower? You won't know this unless you try working the load up to a higher level in the 24" tube, to see if the new rifle will accept a heavier load, and produce a velocity commensurate with the heavier charge! Forget the coincept of "book maximum", as that maximum was developed in a different gun entirely from either of your two!

You are seeking the best-performing loads for your two rifles, both from the viewpoint of velocity and also accuracy! You may have to compromise between acceptable accuracy and possible velocity to get there. But, I would be surprised as hell if these two loads turned out to be the same for the two different rifles, and even more amazed if either turned out to be equal to a load you got out of some book! Book loads are for guidance only-I read all the time "Never exceed a book maximum". This is basically a form of B.S., as you may have noticed that some books' maximums often exceed the maximums published in other, equally authoritative, books!! So which book do you select to believe??


"Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen."
 
Posts: 4386 | Location: New Woodstock, Madison County, Central NY | Registered: 04 January 2005Reply With Quote
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El Deguello,

I appreciate the info. I loaded some more up last night and I'll make another trip to the range this weekend to see how they perform. If velocity is still on the low side, I'll increase the charge in 1/2 grain increments until I start getting velocity closer to the high 2700s and pressure signs. Thanks again for the perspective.
 
Posts: 452 | Location: North Pole, Alaska | Registered: 28 April 2001Reply With Quote
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Picture of Mike_Dettorre
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WHy even worry about it. You would expect a loss of about 30 fps...so you lost an extra 69 fps.

Take a look at a balistics chart between 2700 fps and 2750 fps which is approaximately what you are taliking about...the difference is not even worth worrying about.


Mike

Legistine actu quod scripsi?

Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.




What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
 
Posts: 10164 | Location: Loving retirement in Boise, ID | Registered: 16 December 2003Reply With Quote
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Mike,

I'd like to get advertised factory velocity out of em. Right now it looks like I'm not. Once I hit the range again and chronograph some more I'll have a better idea where the load stands.

I'm not interested in hot-roddin the load. There are too many variables to alter velocity and pressure on any given day. I already ran the trajectory numbers through my Pact ballistic calculator and the difference between 2700 fps and 2818 fps isn't really earth-shattering. I don't have any doubt the lower velocity will do what I need done but on the other hand I don't see much value in handloading ammunition that clocks in lower than anticipated factory velocity. So, we'll see what the chronograph says this coming weekend. Appreciate the input.
 
Posts: 452 | Location: North Pole, Alaska | Registered: 28 April 2001Reply With Quote
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