Slow barrel

N.F.W.M

Well-Known Member
Is there such a thing as a slow barrel ?

I have a barrel that simply put is slow.... very accurate but 150-200fps off published data and others caliber users velocities. Not concerned by this, just interested in others experiences.

Regards

Ed

7mm Rem Mag, 24inch Krieger barrel, 64g N160 pushing 150g Nosler BT at 2840fps.
 
7mm RM and 24" barrel is your problem. Issue is you now have the mag kick but no better performance than something much milder like 7-08. 26" barrels or there's not much point Imho
 
7mm RM and 24" barrel is your problem. Issue is you now have the mag kick but no better performance than something much milder like 7-08. 26" barrels or there's not much point Imho


I thought long and hard before adding the spec and calibre of my rifle to the thread.. Why.... because I didn't want this to turn into a "my calibre is better than yours' thread.

You may struggle to handle recoil in a rifle but many of us do not. Do you think that on commissioning a custom rifle I did no research into calibres and barrel length ? If i and wanted a 7-08 I would have had one made. If I had wanted a 26inch barrel on my 7mm Rem Mag.... It would have one.

Regards

Ed
 
Calm down Sir! It's not about calibres being better than others, and personally I have no issues with the recoil of magnum rifles at all, that's not the point here. The point is simply that a 24" 7mm RM does not reach its full potential due to lower velocities, you also get more unburnt powder, more muzzle flash and more muzzle erosion.

had you done all that research I am surprised as to why you didn't already know this.

i quite simply stated, a short barrel 7mm RM might still shoot great, but it's not going to do anything for you you couldn't achieve in a non mag chambering without a belted case, less wear, less recoil. Etc.

Maybe this upsets you because it's not fun to hear, but it is what it is, and in the end YOU asked the question


I thought long and hard before adding the spec and calibre of my rifle to the thread.. Why.... because I didn't want this to turn into a "my calibre is better than yours' thread.

You may struggle to handle recoil in a rifle but many of us do not. Do you think that on commissioning a custom rifle I did no research into calibres and barrel length ? If i and wanted a 7-08 I would have had one made. If I had wanted a 26inch barrel on my 7mm Rem Mag.... It would have one.

Regards

Ed
 
Calm down Sir! It's not about calibres being better than others, and personally I have no issues with the recoil of magnum rifles at all, that's not the point here. The point is simply that a 24" 7mm RM does not reach its full potential due to lower velocities, you also get more unburnt powder, more muzzle flash and more muzzle erosion.

had you done all that research I am surprised as to why you didn't already know this.

i quite simply stated, a short barrel 7mm RM might still shoot great, but it's not going to do anything for you you couldn't achieve in a non mag chambering without a belted case, less wear, less recoil. Etc.

Maybe this upsets you because it's not fun to hear, but it is what it is, and in the end YOU asked the question


You are entirely missing the point.... Book data for my exact load and for several other loads I have tried are 150-200fps faster than my rifle is producing. These stated loads are using a 24inch barrel. Hence the question about slow barrels

With all other calibers I load for I achieve velocities much closer to what is stated in whichever reloading guide I am using.
 
pietasvenatores, is right NFWN, your 24" barrel is not doing you any favours regarding velocity, that lack of a couple more inches is reducing your actual velocity to those achievable by smaller non magnum cartridges burning less powder.
When we did the load developement for my mates 7mm Rem mag Sendero we were acheiving 3130fps with the same bullet over a stout charge of Vit 160 without any pressure signs.

Ian.
 
You are entirely missing the point.... Book data for my exact load and for several other loads I have tried are 150-200fps faster than my rifle is producing. These stated loads are using a 24inch barrel. Hence the question about slow barrels

With all other calibers I load for I achieve velocities much closer to what is stated in whichever reloading guide I am using.

Don't believe everything you read in a book, that's why they are called reloading guides and not reloading absolutes.:)

As others have already pointed out every barrel is different and will produce different velocities with the same load. I have two double rifles and both produce slightly different but consistent differences when the same loads are fired from each barrel. The consistency of the difference is such that you could almost predict within a few feet per second what the velocity would be from the second barrel after shooting the first, so I suppose you could possibly say that there is such a thing a "slow barrel".
 
The "progressive burning" rifle powders used in contemporary sporting cartridges are totally "burnt" in the first 1-2" of any barrel after the leade. The barrel length has SOME effect on average velocities, due to the greater expansion of the propellant gases over time, but, again, this would amount to perhaps 40 fps between 24-26" tubes.

The issue HERE is that the 7mmRM has a reputation for great variation in ballistic results, some barrels ARE "slower" than some others and the first approach to finding the optimum load for ANY rifle, is to undertake a load testing programme with various powders/bullets and even brass to find it. I would try IMR-7828, first, the original fuel for the "Big Seven" when Remmy introduced it, also RE-25 and H-1000 or MagPro depending on what you can obtain.

I have owned three different 7mmRM rifles, all Rugers and loaded for several others, as well. I do not care for the round, am a .280Rem. and now a .280AI fan, but, what YOU like is what counts, eh! :)

You will find that most "premium" bullets, Nosler Pts. Swift A-Frames, etc, will tend to give slower velocities than the "cup and core" types; so, be very cautious when extrapolating data from, for example, Hornaday to Swift bullets.

HTH, sorry if I am reiterating what you already know, but, trying the above powders really is worth the effort.
 
Are you getting pressure signs with your current load or can you slowly increase the charge a bit?

Good advice or even try one of the Vit. double base powders N560 or N550.

But to answer your question, yes.
I have personally seen barrels chambered with the same reamer, same barrel manufacturer, in the same calibre built by the same gunsmith that shown significant differences. But these weren't in 7RM.
 
Every barrel is different. Even if the same length, profile etc. They may give the same velocity figures but more often then not won't.
Same goes for twist rate, my old 222 1-14" stabilised 62-63 grain bullets fine, many do not.
 
The "progressive burning" rifle powders used in contemporary sporting cartridges are totally "burnt" in the first 1-2" of any barrel after the leade.

Where did you get this bit of information? If it were true everyone would be shooting the shortest legal barrel lengths. Anyone who has fired a shot across a field covered with snow from a short barreled rifle has seen unburnt powder with their own eyes, not opinion, just fact.

SS
 
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Surely if that was the case, then moderators would fillup with unburnt powder!
The reason for different barrel lengths and rate of twist etc is bullet stability and total expansion of gases.
Any powder that exits the barrel unburnt can only be the result of poor primer choice! poor powder.
But even more likely is the fact that powder residue sometimes looks like unburnt powder.
 
Surely if that was the case, then moderators would fillup with unburnt powder!
The reason for different barrel lengths and rate of twist etc is bullet stability and total expansion of gases.
Any powder that exits the barrel unburnt can only be the result of poor primer choice! poor powder.
But even more likely is the fact that powder residue sometimes looks like unburnt powder.

Moderators can fill with unburnt powder if the barrel is too short and the buring rate for the powder slow. Back to my question, where did you get the information?

SS
 
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Good advice or even try one of the Vit. double base powders N560 or N550.

But to answer your question, yes.
I have personally seen barrels chambered with the same reamer, same barrel manufacturer, in the same calibre built by the same gunsmith that shown significant differences. But these weren't in 7RM.

Have a load using N560 but at even a bit over max (worked up slowly and safe in my rifle etc etc) is still only achieving 2915fps.
 
Is there such a thing as a slow barrel ?

I have a barrel that simply put is slow.... very accurate but 150-200fps off published data and others caliber users velocities. Not concerned by this, just interested in others experiences.

Regards

Ed

7mm Rem Mag, 24inch Krieger barrel, 64g N160 pushing 150g Nosler BT at 2840fps.

I had a .260 which was slow.
It shot well for the most part but had some annoying habits.
Switching from N160 to N550 made it a lot more lively but truthfully, none of the loads represented the manuals results.

If it works, shoot 'n smile.
If you want more speed then work it up using load length and perhaps a different powder.

There are so many variables in this game it makes comparing your experience to what the book says a little pointless.

I'd also take the loading guides as guides, for example the 2013 Viht book has your load over the max by some ways but clearly you're still here...
:)
 
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