Shortening barrel length

[TOP PREDATOR]

Although the actual act of cutting the barrel goes into more detail here: LOW BUDGET .22 SIL. RIFLE/TRAINER - shortening the barrel , this post goes more into the range report differences of shortening the barrel.

Whether you call it a 20" barrel as advertised, 19.75" measurement from the muzzle to receiver, or 21 1/8" by inserting a cleaning rod into the barrel againt a closed bolt, then marking and measuring the rod, we'll call it the "stock length barrel", -1", and -2".

Rifle used: Savage MKII "F" sporter barrel - 2lb 12oz trigger - shot of harris bipod and rear bag - 12x on the optic. Used 2 ammos, CCI blazer (high velocity) and Aguila Golden Eagle Match rifle. 10 round groups were shot, barrel was dry swabbed "clean" before an ammo change. At 50 yards, 1" bull was used, at 100 yards 1.5" bulls.

Groups with the stock length barrel - weather 65 deg. F., 35% hum., 3-7 mph wind from 8:00, mostly sunny.

Groups with the -1" and -2" - weather 45 deg. F., 47% hum., 3-10 mph wind gusts 3:00.

FPS per length - Chrony was set at 10 ft away from muzzle:

<span style="text-decoration: underline"><span style="font-weight: bold">Stock barrel</span></span>

Blazer - 1241 FPS avg., (range of 1221-1256 FPS)
Aguila Match Rifle - 1101 FPS avg., (range of 1080-1126 FPS)

<span style="text-decoration: underline"><span style="font-weight: bold">-1" shortening</span></span>

Blazer - 1216 FPS avg., (range of 1207-1221 FPS)
Aguila Match Rifle - 1083 FPS avg., (range of 1062-1095 FPS)

<span style="text-decoration: underline"><span style="font-weight: bold">-2" shortening</span></span>

Blazer - 1217 FPS avg., (range of 1173-1239 FPS)
Aguila Match Rifle - 1082 FPS avg., (range of 1062-1111 FPS)

50 Yard groups - stock length top, -1" middle, -2" bottom

100 Yard groups - stock length top, -1" middle, -2" bottom

It appears (in general) that the groups of both the ammos shrank at both 50 & 100 yards. From stock length to -1" there was a 25 FPS drop in the HV Blazer, and 18 FPS in the Match velocity Aguila. When shortened another inch to 2", no significant drop in FPS, but more consistant on paper. Oddly the -1" and -2" barrel length RAISED the POI an average of 1.5" in the HV and remained the same for the match ammo at 50 yards. On the contrary, at 100 yards the POI on the match ammo changed about 1.5" higher - STRANGE!

BULLET DROP - (shooting at 100 yards with the 50 yard setting) the amount of bullet drop changed, but only slightly by about -.75" with the shorter barrel.

OVERVIEW:

1. Shortening the sporter barrel decreases group size with HV and match ammo.

2. FPS was reduced with the initial -1" (around 20 FPS), but the second inch reduction didn't show much more as i would have expected (I figured it would be -40 FPS, but was nearly identical to the -1" FPS).

3. Balance and handling was improved.

So will further shortening the barrel decrease group size more, stay the same, or actually hurt?

After the initial drop in FPS, wouold FPS stabilize until a more "extreme shortened barrel" length is reached?

Is it that the shorter barrel is "stiffening" up the sporter styled barrel by reducing "whip" and harmonics producing better groups?

I'm not sure at this point, but shortening my sporter barrelled rimfire by 2" actually improved my groups at both 50 and 100 yards, high velocity and match / standard velocity.

Although I'm tempted to shorten the barrel more, I find it best to stop here on the side of caution - for now. If there is a certain point where shortening a barrel starts to detriment performance, I don't want to find it, 'cause when you pass it, you can't add more barrel. I've heard many having success with a 16" barrel, but for now my 2" inches off will serve me well - at least until I bug myself enough to go to 16". If I do, I'll update with the results.

 

[Greg Langelius *]

Re: Shortening barrel length

My guess, groups will continue to tigbten up as length decreases.

What was used to shorten the barrel, and did you use the deburring tool to clean up the crown?

Greg

 

[SmallBoreSnipers]

Re: Shortening barrel length

Very nice work and info. I've considered shortening my barrel but I'm concerned that the high velocity .17 HMR won't stabilize correctly.

 

[Oodin]

Re: Shortening barrel length

Greg,

The barrel shortening process is detailed in the link provided in the OP.

 

[xxtagnastyxx]

Re: Shortening barrel length

Thank you for doing this. Shortening the barrel on my 22 trainer is on my list of things to do now.

 

[Greg Langelius *]

Re: Shortening barrel length

Oodin;

Thanks, got it now.

Wow!

Greg

 

[SPAK]

Re: Shortening barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SmallBoreSniper</div><div class="ubbcode-body">Very nice work and info. I've considered shortening my barrel but I'm concerned that the high velocity .17 HMR won't stabilize correctly.</div></div>

I'm considering the same thing right now. I just had my savage mark II heavy barrel cut down to 16" and while I haven't done any group testing I've been very happy with my accuracy at 50 and 100 yards. Definitely no worse than the stock barrel. But maybe a little bit louder.

I have a savage 17hmr with a heavy barrel that I will probably cut down to 16" as well. CZ makes a 16 barrel for their 17 hmr as an option.

I don't have the link but I think VarmintAl's website has a graph with the velocity results of 17hmr barrels from 21" down to 10" I think. While you do lose some velocity it looks like the ES shrinks a little bit with the shorter barrels between 15-17".

I think I'm gonna give it a try at 16" with the 17. It seemed to do very well with my .22LR.

 

[JoeMartin]

Re: Shortening barrel length

Interesting, very interesting!

I was always under a personal belief that the longer barrel would stabalize the High Velocity round to Standard Velocity, and that Standard Velocity in a longer barrel would react as Sub-Sonic does in the shorter barrel allowing transition within 15 to 17 yards (depending on conditions and sea level elevation).

This is one reason I always felt that Standard Velocity performed best in a 21" or longer barrel. I will watch your results with this rifle TP as there is much to learn from this.

Thanks for taking this bold step in cutting your barrel back!

 

[SmallBoreSnipers]

Re: Shortening barrel length

That's pretty cool. I'll have to look at that info on Varmint Al's. I have a 22" barrel on my 17 that I've been wanting to cut down to somewhere around 18".

 

[SPAK]

Re: Shortening barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SmallBoreSniper</div><div class="ubbcode-body">That's pretty cool. I'll have to look at that info on Varmint Al's. I have a 22" barrel on my 17 that I've been wanting to cut down to somewhere around 18". </div></div>

I like the shorter barrels, they handle better and cut a little weight....I figure if CZ makes a 16" barrel it "shouldn't" be very detrimental to accuracy.

 

[SPAK]

Re: Shortening barrel length

http://www.varmintal.com/17hmr.htm

found the link, scroll down about half way down the page.

 

[SmallBoreSnipers]

Re: Shortening barrel length

I see the blue chart that shows rifle weight, twist, bullet diameter, mass, velocity, spin and so on, but it doesn't actually list any barrel lengths. Are you suposed to figure from this chart or am I looking at the wrong thing?

 

[TOP PREDATOR]

Re: Shortening barrel length

keep scrolling down, you'll see it. about mid way through the post has barrel length and fps. would have been nice if they listed group size.

here's a barrel article from chuck hawks, includes some length stuff, but again no group sizes:

http://www.chuckhawks.com/rifle_barrel.htm

a copy and paste as it concerns .22lr

To my mind it is hard to justify barrels shorter than 20 inches for any purpose. I have owned rifles with 18-19 inch barrels and in every case I wished that they had come with at least a 20 inch barrel. Very short barrels of standard contour (not bull barrels) tend to make the rifle muzzle light and unsteady to hold and swing. I like a rifle to balance between my hands, not toward the butt. Even .22 rimfire rifles balance better with 20-22 inch barrels, although in this instance the longer barrel has no ballistic advantage, since the .22 LR cartridge burns all of of its powder in about 16 inches. Very short barrels also increase the muzzle blast from high intensity cartridges to very annoying levels and the velocity loss is excessive.

Velocity loss (or gain)

It is worth noting that the velocity figures published in ammunition brochures and reloading manuals are sometimes taken in barrels different in length from those supplied on many rifles. I have seen various estimates of how much velocity is lost (or gained) when a barrel is not the same length as the test barrel in which a cartridge was chronographed. Here are some of them.

The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.

Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.

Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:

MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.


The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:

For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.

The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:

The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.

For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:

The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
The average loss for the .30-06/180 grain bullet was 15 fps per inch.
The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.



*** "For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.***


that's why i like testing myself. although the above tables are on centerfires, i didn't meet some of the numbers on the .22lr with the high velocity Blazer - 1241 FPS avg., (range of 1221-1256 FPS) and the Aguila Match Rifle - 1101 FPS avg., (range of 1080-1126 FPS) about 18-25 fps lost on both with the first 1" lopped off.

the second inch not much difference.

i would think that at least from a MV standpoint, what ever the caliber bullet, weight, and cartridge, there would be some correlation betwwen the rimfire and centerfire.

guess not.

i would love to find out that if enough barrel is cut back that it would "rob" enough High velocity ammo FPS to put it into the standard or match velocity range. perhaps that would help with stabilization bringing reg HV ammo below the transsonic barrier, but i don't have the guts to cut mine down that far yet.

 

[dlc356]

Re: Shortening barrel length

I had my 452 Varmint threaded only to find out that the crown was not square to the bore. This led to very light baffle strikes and awful accuracy. I contacted Hooper and after talking with him decided to shorten it to 16 1/4". He cut and re-crowned it and it's a tack driver. It groups better than factory now and I couldn't be happier. BTW, his threading and thread protector are top notch (shameless plug for a fellow member

)

My only long barreled .22 is my 40X. If it didn't shoot so good I'd probably lob a few inches off of it too. However, I'm a firm believer in, "If it aint broke, don't fix it." As long as it makes little bitty holes I'm not going to touch it. If accuracy ever drops off, I'll think about it but until then I'm good. A .22 doesn't need that much barrel to burn off the powder and in (my experience), most cases a shorter barrel will shoot extremely well.

 

[Hooper]

Re: Shortening barrel length

My experience with .22lr has shown that a 16" barrel with a nice crown is best.

Glad you like the work I did David. I will have my 452 trigger guard out soon.

 

[SPAK]

Re: Shortening barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dlc356</div><div class="ubbcode-body">I had my 452 Varmint threaded only to find out that the crown was not square to the bore. This led to very light baffle strikes and awful accuracy. I contacted Hooper and after talking with him decided to shorten it to 16 1/4". He cut and re-crowned it and it's a tack driver.</div></div>

just curious was this a 17 hmr or a 22LR???

 

[dlc356]

Re: Shortening barrel length

It's a .22.

Hey Hooper, thanks again. I'll be keeping an eye out for a thread on the trigger guards.

 

[SPAK]

Re: Shortening barrel length

Well, I thought I'd add my experience to the thread. I had a savage 93r17 heavy barrel cut down to 16.25". Risky I know, but in anycase, 10 shot group at 100 yards measured right around 1.1MOA with the 6 shots in a .6 MOA group in the center. I had 2 shots that went low that opened up the vertical to 1 MOA. The rest of the group had .6 MOA in vertical and 1.1 MOA in horizontal. I wish I had before and after pics but I dont have any of the before. I'll see if I can't post some pics of the group I shot today.

FWIW with me being the shooter I couldn't tell if the accuracy any better than it was before at 21" of barrel length. It still shot just as well as it did before, which is what I was hoping for. It was definitely a little louder and the the chrony read an avg velocity for the ten shots of 2480 fps using hornady 17gr vmax.

My Savage mark II cut down to 16.25" shoots very well at 50 yards for sure. Hovers right around .6MOA for 5 shot groups. I haven't shot it yet at 100 yards for groups yet but I will.

Shorter barrel is definitely nicer to carry around

 

[RicosRevenge]

Re: Shortening barrel length

Has anyone cut down a 40X-HB? I've heard there is a "choke" point near the muzzle where it restricts and if you chop the barrel it completely changes the "magical" way they shoot.

 

[gszeto99]

Re: Shortening barrel length

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RicosRevenge</div><div class="ubbcode-body">Has anyone cut down a 40X-HB? I've heard there is a "choke" point near the muzzle where it restricts and if you chop the barrel it completely changes the "magical" way they shoot.

</div></div>


Are you talking about me and my 40x-HB cut down experience...

Gene