Few questions about modifying KAC SR25

[TheGerman]

Only in theory right now as I have other projects going, but was thinking about changing my completely stock KAC SR25 around a bit to better fit what I was wanting to do and wanted to see if this was feasible or just retarded.

I have the 20" 1:11 twist ER with the URX rail. A few ideas I've been kicking around:

- I plan on using this to 800 yards max as well as utilizing the 1.1-8 optic on it for shorter range shooting. Wanted to try and make this more of an all around 308. Any further and I have better options, especially for a 308. I was thinking I could have the barrel cut back to 16". Other than a loss of velocity, how would this affect the rifle if at all? Reasoning here is that I see many 16" to 14.5" 308 AR10 type platforms on here and the extra length/weight doesn't give me much added benefit and I'd be willing to lose the 4 inches.

- If I had 4 inches removed, that would leave roughly 1.5 inches in-front of the beginning of the gas block. I am assuming I would need the gas block/system moved and/or changed or can this be left alone?

- SOCOM 7.62 brake and SOCOM suppressor over the MAMS and KAC suppressor. Am I wrong here? Have not seem many good reviews on the KAC.

- Would the shorter barrel cause issues with the gas system if suppressed?


Wanted to see if all of this was doable and didn't have any real drawbacks. Besides the change in velocity, would the shorter barrel have anything negative going overall? If I did do this I'd send it to boltcarrier, but wanted to see what the consensus was on something like this before I tried to do something stupid.

 

[GH41]

I'd say don't do something stupid. Even if you get it to work you will have transformed a valuable KAC rifle into a Frankengun!

 

[Rstrick0352]

I would look into getting a barrel at the length you want and not cutting the knight barrel down. Unless the knight has something proprietary about it where you can't get an off the shelf barrel for them. That way the gas port on the new barrel will be matched to it's intended length and you will always have the factory knight barrel to put back on for resale if you desire. Just my .02. If not, I wouldn't hesitate to cut and thread and possibly drill out the gas port on your current barrel if that was the route you decided. It's a gun and it was meant to be shot.

 

[Mack7.62]

Doable and no real drawbacks. Melvin Purvis is the one to shorten the barrel and can dimple it also, I believe Boltcarrier uses him for barrel work, gas block is fine but port may need drilling. The KAC suppressor works good but the biggest drawback is that they are caliber specific, the 5.56 and 7.62 MAMS are different diameters so you cannot use the 7.62 suppressor on a 5.56 rifle.

 

[Double3]

Doable and no real drawbacks. Melvin Purvis is the one to shorten the barrel and can dimple it also, I believe Boltcarrier uses him for barrel work, gas block is fine but port may need drilling. The KAC suppressor works good but the biggest drawback is that they are caliber specific, the 5.56 and 7.62 MAMS are different diameters so you cannot use the 7.62 suppressor on a 5.56 rifle.

Marvin Pitts?

 

[Mike_Honcho]

Ask yourself what you're really gaining by doing this? If whatever that is is really worth it to you, you'd better off not hacking it up. Sell it off and buy an APC when it is available.

The value of a KAC is an unmolested unit. Do something weird to it and it the value is akin to a 'kit' Ferrari on a Camaro frame and drive train.

 

[Masked]

Doable and no real drawbacks. Melvin Purvis is the one to shorten the barrel and can dimple it also, I believe Boltcarrier uses him for barrel work, gas block is fine but port may need drilling. The KAC suppressor works good but the biggest drawback is that they are caliber specific, the 5.56 and 7.62 MAMS are different diameters so you cannot use the 7.62 suppressor on a 5.56 rifle.

Per the KAC, yes...They're not really backwards compatible.

Per the Socom 762-RC, they are.

762 RC suppresses 5.56 better than most 5.56 suppressors out there...Can even handle the win mag.

 

[Tx_Flyboy]

What exactly are you going to gain by going from a 16" rifle to 20" rifle?

How often will you be clearing rooms or other CQB activities?

How often will you be shooting 800yards?

What is the reality of most of your shooting?

The 20" rifle is better than the 16" rifle as distance increases...whereas, the advantage of 16" rifle over the 20" rifle in "CQB" is much overstated....there is also the fact that you are cutting off the rifle at the at the thinnest diameter making the weight savings no more than a few ounces while drastically changing the balance of the rifle.

IOW, this is a bad idea. you are better off with a 16" upper or a installing a 16" bbl so that you preserve the resale value of your rifle.

If this rifle comes with an adjustable stock, then honestly, i don't see the point of a 16" rifle, except to look cool on the internet.

 

[2680fps]

Why screw up a perfectly good rifle? Did you buy the wrong one, I.e. should you have paid the extra $1k and bought the ECC?

Don't mean to be brash but that is what I am reading. Cutting down the barrel, 1-8x optics....... Sell it and get the right one before you fuck it up.

 

[Benito]

No way would I ever modify a KAC.
These are factory guns, with lots of proprietary parts, covered by warranty.

If you modify it, the warranty will probably go out the window and the value will most likely decrease should you decide to sell it.

If you really want a shorter barrel, just sell your 20" SR-25 and get a 16" SR-25.

I like 16" .308's, but a 20" SR-25 is still a bangin' gun, and not something I would want to tinker with.

 

[sendit300]

It's your gun! This is worth that, that is worth this... Worst thing that could happen is you'd learn a lot about your gun, and the people who work on gas guns as you sort kinks out. If you're not shooting the 20", want to try something new, aren't owning a KAC to measure... You get it. Your port size and buffer weights are the same in the 20" as they are in the 16". Buffer should be 4.6oz, port size is .091. You may need to open the port up a little if you have minor issues once you turn it down, open to .093, progress slowly. Have Fun!

 

[jasonfaz]

Hell yes my man, I'd do it! I'd wait till I got my can though.....and NO the Surefire would not be the better choice over the QDC+MAMS. IMO the QDC and MAMS is the best suppressor/brake combo in existence as of current day. The reason you can't find one is because the military gobbled up the first 10000 cans of the press. I finally found one 6 weeks ago and should have it by summer of '15. I threw a few rounds through one at a shoot a few months back and it was beyond impressive. That would be the perfect setup for a 16" intermediate length DI 308. Do it, but do it after you get your can!