Go | New | Find | Notify | Tools | Reply |
one of us |
I worked up to the max load in my .257 Bob using the Barnes 100 gr. TSX bullet. On two occasions, I ran the load (44.5 gr. of IMR-4350) over the Chrnograph and the velocity was 2851 FPS average. According to the barnes manual, they got 3124 FPS with the same load with a 24" barrel. Allowing for my 22" barrel, I feel that 273 FPS difference is a bit out of line. When I tried a half grain more, I started to get signs of too high pressure. Work up from the starting load showed everything including velocity gain as being perfectly normal. I'm going to run a few more over another chronograph this time and see if that makes a difference. Paul B. | ||
|
one of us |
Call and ask `em..... I`ve seen ~200 fps difference in velocity with a couple loads in my rifles from what the books said I should expect. The spreads seemed to shorten though with a switch to another powder or bullet. Your rifle doesn`t have a SAAMI min chamber and bore, nor are you useing the same components in the same atmospheric conditions. The chrono`s used might both be slightly in err and add some stacked numbers to the spread. Your chrono too likely gave a speed at a given distance from the muzzle, where the book vel was adjusted to the muzzle. The difference isn`t much but everything adds up. ------------------------------------ The trouble with the Internet is that it's replacing masturbation as a leisure activity. ~Patrick Murray "Why shouldn`t truth be stranger then fiction? Fiction after all has to make sense." (Samual Clemens) "Saepe errans, numquam dubitans --Frequently in error, never in doubt". | |||
|
One of Us |
Lie is a nasty word when more likely it is a typographical error of which they are more than capable of plenty. However, what Ol'Joe has pointed out is also a hard fact of life that pressure test barrels often do not correlate in a linear fashion to factory or custom barrels. For what it is worth, I am getting 140 ft/sec too much velocity in a H4895 load with 77 grain MK's according to the Hodgdon web site. Of course I didn't complain about that... Member NRA, SCI- Life #358 28+ years now! DRSS, double owner-shooter since 1983, O/U .30-06 Browning Continental set. | |||
|
one of us |
Paul B ----- Always remember one important thing, all the manuals tell you is what their test barrel results were the day they tested. Their componants are listed, it is important to notice that also. I shoot two rifles of the same chambering, the speeds are 50-150 fps different on all loads. Both are custom barrels. It is also important to read more than one manual. Each manual tests their bullets, changing the bullet from one manufacturer can make a big difference. Good luck and good shooting. phurley | |||
|
One of Us |
I have seen differences similar to that with other manuals, low & high. I beleive that there are too many varibles to list but it is rare to duplicate performance listed in the loading manuals. | |||
|
One of Us |
I don't think it is a lie...I think it is variation in the bbl and other factors. I achieved Barnes Max for a 180 grn 308 Win TSX load out of a 22 inch bbl 2 grains under max. I was also foolish enough to not start low and blew a primer from high pressue at 1.2 grains under max on 46.3 grn load 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. | |||
|
one of us |
Matching the omponents is just as important. I have some 7mag brass made by Norma that has 7% more capacity than it's Win or Fed equivalent. Pretty easy to "exceed book speeds" with that brass! I just checked my 358 Norma brass, too, and the Norma brass again has 7 grains more capacity than reformed Win 338 brass. If I were in the business, I would for darn sure list loads using the reformed brass, because some knot-head out there is going to use it and start at max book. JMO, Dutch. Life's too short to hunt with an ugly dog. | |||
|
One of Us |
I've only tried Barnes tables with one caliber (404 Jeffery) but I get about 150 fps to 200 fps slower velocities than they. Of course they're using a 26" barrel and mine is 24". _________________________________ AR, where the hopeless, hysterical hypochondriacs of history become the nattering nabobs of negativisim. | |||
|
one of us |
On average, I've just come to realize that if a load book has a listed velocity, I should subtract about 200fps and that is what I'll get. Ted Kennedy's car has killed more people than my guns | |||
|
One of Us |
Dutch, Interesting you brought up the brass. I was using hornady brass. I have never checked the volume but hornady brass consistently weighs about 10-15 grns lighter than most brands I have weighed...so therfore these pressure signs in my view were even more unusual. 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. | |||
|
one of us |
I have a .223 load that is faster than the Hornady book, and a .308 load that is slower. Just the nature of the game. | |||
|
one of us |
I once read an article written by Rick Jamison. In it, he wrote he found as much as 120 fps difference between lots of the same powder. Another article I read on-line a couple months ago made the claim that ammo manufacturers specify there can be as much as 90 fps variation between published velcoities and actual ones. When we add the variables within barrels (based on their length and chamber and bore dimensions) and ammo components, it's not surprising we get velocities that differ from published load data. This past summer, I worked up some loads for my new 338 WM. I wanted one that would work well in both my 338 WMs. The load clocked in 127 fps slower in my rifle with a 24 inch barrel than the one with a 26 inch tube. All these variables together can sure make a big difference. | |||
|
one of us |
at one time i was loading for 3 different 30-06s, with the same load,..all 22"in tubes. from the fastest to the slowest they shot 150 FPS different over a chroney.. all 3 different makes. the fastest was a weatherby vanguard at 2912. | |||
|
One of Us |
The old Hodgdon #23 has a load for the 6.5x55 with a 140 gr bullet listed as 52 grains of H4831 getting 3010 fps with a 28in bbl. Don't even think about trying that one. Hodgdon #25 shows 45grns of H4831 at 2392fps. Like they say, stuff happens. | |||
|
One of Us |
It is unrealistic to expect that two different barrels will give the same MV with the same load, even two which are produced on the same equipment one after the other. We often give numbers purporting to predict the velocity loss to be expected when using a load in a shorter barrel, but as a matter of fact, it doesn't always happen that way. Sometimes, a shorter barrel will produce equal or even greater velocity than a longer one, and no-one can figure out why this happens. I don't think the Barnes performance figures are anything but further proof that each rifle is an individual.... "Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen." | |||
|
Powered by Social Strata |
Please Wait. Your request is being processed... |
Visit our on-line store for AR Memorabilia