RE17 vs. Barrel life
- Thread starter memilanuk
- Start date
jonbearman
I live in new york state,how unfortunate !
This should be interesting,I use re-15. Now you got me lworried,LOL. I gotta watch this carefully. Thanks for asking this question.
One datapoint... I don't have a borescope, but I have a .260 barrel with about 1000 rounds through it. Almost all those rounds were loaded with RL-17, around 42.5gr; about half 139gr Scenars and half Berger 140gr HPBT-LR's. I only shoot the Bergers through that barrel now.
Measured using the Hornady COAL tool, I have to load the bullets 0.03" longer than when the barrel was new to touch the lands. Don't know if that's typical at that round count for a .260. Accuracy is still very good; I figure the barrel will go for at least another 1000 rounds.
Measured using the Hornady COAL tool, I have to load the bullets 0.03" longer than when the barrel was new to touch the lands. Don't know if that's typical at that round count for a .260. Accuracy is still very good; I figure the barrel will go for at least another 1000 rounds.
bigedp51
RL17 is a double base powder and produces more energy than a single base powder by weight.
The new M118 Special Long Range sniper ammunition uses double base RL15 and they are not complaining about barrel wear.
The new M118 Special Long Range sniper ammunition uses double base RL15 and they are not complaining about barrel wear.
bigedp51 said:
It's not just that it is double base, and can't be compared to RL-15, since other than being marketed by the same company, they are totally different powders. In the article on this site about RL-17, it is compared to two other double base powders with similar burn rates, H4350 and H4831sc, and gets higher velocities than either. I certainly get higher velocities with RL-17 than H4350 in my .260.
There being no such thing as a free lunch, that velocity must have some sort of cost, as memilanuk writes, and I too am curious what that cost is.
I have a Savage 12F .308 with 815 rounds of RL17 behind Berger 210 BT-LRs. Barrel is a 30" McGowen full bull 10" twist. The loads are full pressure and generate 2600 in Lapua brass and 2700 in Winchester brass. The Win brass holds 1.8 grains more water than the Lapua. My borescope show superficial surface checking appearance for the first inch and nothing else. It does not look different than my other .308 barrels at this point. Judging from present condition, I estimate 3000-4000 rounds. YMMV
Not to answer for Jason, but...
Regardless of progressivity and extended pressure, peak pressure and temperature will still occur in the throat area. Peak pressure is no higher than conventional double-base powders or we would see brass problems. Since the throat is not "seeing" higher temperature or pressure than usual, there should be no specific longevity reduction. The affected area may be extended further down the bore but the throat will still be the deciding factor.
Regardless of progressivity and extended pressure, peak pressure and temperature will still occur in the throat area. Peak pressure is no higher than conventional double-base powders or we would see brass problems. Since the throat is not "seeing" higher temperature or pressure than usual, there should be no specific longevity reduction. The affected area may be extended further down the bore but the throat will still be the deciding factor.
Reloder 17 shares nothing in common with other Alliant powders other than the nitrocellulose and nitroglycerine base. It is a product of Nitrochemie AG of Switzerland and uses a technology that permeates the entire kernel with deterrent, not just the surface. As Jason noted; this enhances progressivity and produces a greater area under the curve, sustaining pressure longer than other propellants and producing higher velocity.
bigedp51
Deja vu all over again................
http://www.accurateshooter.com/forum/index.php/topic,3748839.0.html
http://www.accurateshooter.com/forum/index.php/topic,3748839.0.html
For what it is worth, I just replaced a 6.5/284 barrel at 956 rounds with a steady diet of maximum charge of Re17/142 SMKs. That seems to be in keeping with the barrel life of others using H3450 in the same application. The only maintenance I performed was to clean every 200-400 rounds to bare metal and use JB Bore paste and polish every 500-600. Throat showed cracking by 500 rounds (probably sooner) but the polishing kept it accurate.
Frankly, the life of this barrel is no worse than any other high intensity cartridge I use (.243, 7mm Mag., 300 WSM) My .30-06 barrel showed pretty much the same condition at 600 rounds and is still accurate at 1300 rounds.
Frankly, the life of this barrel is no worse than any other high intensity cartridge I use (.243, 7mm Mag., 300 WSM) My .30-06 barrel showed pretty much the same condition at 600 rounds and is still accurate at 1300 rounds.
I don't know the physics of barrel wear. But, taking a common sense approach, without the large pressure spike that you generally get with other powders at the beginning of the burn, I would think, if it did anything at all to throat errosion, it would lessen it due to the fact that the pressure is lower when the bullet meets the lands.
In addition to trying, fairly unsuccessfully, to shoot a 243 WIN bench rest gun, I also have a Swiss K31 that I use for vintage silhouette and Garand matches. I use RL-17 it this gun as it is the exact same powder used in the GP-11 Swiss Military ammunition. The GP-11, by the way, is considered near match quality.
Anyway, the surplus K31 rifles that have found there way to the states have a lifetime of shooting in them. The stocks are usually pretty beat up, supposedly from using the rifle to knock snow off the troopers hob nailed boots. But, the rifling in the barrels are mostly uniformly pristine! This after a lifetime of shooting military ammunition using RL-17 powder and non-corrosive primers. Also, these rifles have been cleaned using only a proprietary grease for both cleaning the bore as well as lubricating the working parts.
I am going to work up a load for my 243 WIN using RL-17 and my gun's favorite 107gr SMK!
Anyway, the surplus K31 rifles that have found there way to the states have a lifetime of shooting in them. The stocks are usually pretty beat up, supposedly from using the rifle to knock snow off the troopers hob nailed boots. But, the rifling in the barrels are mostly uniformly pristine! This after a lifetime of shooting military ammunition using RL-17 powder and non-corrosive primers. Also, these rifles have been cleaned using only a proprietary grease for both cleaning the bore as well as lubricating the working parts.
I am going to work up a load for my 243 WIN using RL-17 and my gun's favorite 107gr SMK!
bigedp51
I have removed my postings said in anger.
To Mr. Moran my apologies, I don't love the smell of cordite in the morning.
In an old Enfield rifle you can't seat your bullets long and fire form your cases anymore because you don't have any rifling left to push against. :'(
To Mr. Moran my apologies, I don't love the smell of cordite in the morning.
In an old Enfield rifle you can't seat your bullets long and fire form your cases anymore because you don't have any rifling left to push against. :'(
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