Bump saw build?

[Joe Link]

Seems like the biggest issue they are having is light triggers and gas tubes breaking.

If it didnt look so goofy, I'd toss the bipod on my lwrc. I can imagine a piston would run this concept 100% better.

I think you might have to do that. You know, for science

 

[michaeljr]

I think you might have to do that. You know, for science

If anyone has a beta mag or d60....let's find a spot with a good clearing. Get some targets waaaay out. Lwrc makes great barrels, I'm curious to see how it would do accuracy wise burst fire at say 500m

 

[Brutus57]

Don't underestimate the morale effect on a foe with what sounds like MG fire. So there's that practical application too, if SHTF.

Brutus Out

 

[bolus]

A quick update on this project. Too rainy to take video today but the JARD trigger now in a proper lower runs like a charm. I'd call the bump saw project a success. Building one means some trial and error (and a little practice).

 

[Member 34319]

A quick update on this project. Too rainy to take video today but the JARD trigger now in a proper lower runs like a charm. I'd call the bump saw project a success. Building one means some trial and error (and a little practice).

Awesome. Looking forward to seeing this run on video or in person!

 

[bolus]

Awesome. Looking forward to seeing this run on video or in person!

My step son is sort of a bump saw savant. he could vary the rate of fire just by how much forward pressure he put on the rifle. More forward pressure, the faster it runs. Like revving an engine.

 

[Camelfilter]

I'm curious as to what the current legalities are for slide fire/bump fire stocks in say California. What, if any, "real" future legal concerns for us in Oregon or folks up in Washington.

--I've had a slide fire stock in my "cart" over on midway for a while now. Just haven't had anything I "need" to buy, so it's just been kind of on standby.

Thanks.

 

[wired]

If your rile can use a pistol grip it can use the slidefire stock in California. It is a sliding stock and does not affect how the gun fires. It does not make it into a machinegun or anything else besides a standard semi auto that you can pull the trigger faster yourself with. I dont foresee anything changing in Oregon or Washington.

 

[Camelfilter]

If your rile can use a pistol grip it can use the slidefire stock in California. It is a sliding stock and does not affect how the gun fires. It does not make it into a machinegun or anything else besides a standard semi auto that you can pull the trigger faster yourself with. I dont foresee anything changing in Oregon or Washington.

Makes sense, thanks.

 

[Joe Link]

quite the challenging build. So the first trigger was too light and would drop the hammer before the bolt was closed. Today using a standard cmmg trigger the pull distance was too long and I could only get a few double shots. So I need to find a trigger with a pull and reset somewhere in between. I might have to ditch the 80% receiver and go with a normal one and pull one of my geissele triggers out of another gun to try that. Im going to get this thing to run reliably.

A quick update on this project. Too rainy to take video today but the JARD trigger now in a proper lower runs like a charm. I'd call the bump saw project a success. Building one means some trial and error (and a little practice).

I'm (slowly) collecting parts for one of these myself. With your trigger issues in mind, I picked up a KE Arms DMR trigger for $124 on BF. I figured that since it seemed to work well in their build that it was the way to go. Is there a reason you went with the JARD over it, considering they're both about the same price?

I've never assembled an AR15 upper before, and it seems like the offerings of 18"-20" heavy barrel complete uppers is fairly limited. I could wait until PSA gets some in stock, or take begin collecting parts to build my own. Any suggestions here?

Any issues with the short bipod? Would a taller one like in the video be better?

 

[bolus]

I'm (slowly) collecting parts for one of these myself. With your trigger issues in mind, I picked up a KE Arms DMR trigger for $124 on BF. I figured that since it seemed to work well in their build that it was the way to go. Is there a reason you went with the JARD over it, considering they're both about the same price?

I've never assembled an AR15 upper before, and it seems like the offerings of 18"-20" heavy barrel complete uppers is fairly limited. I could wait until PSA gets some in stock, or take begin collecting parts to build my own. Any suggestions here?

Any issues with the short bipod? Would a taller one like in the video be better?

I did the JARD because I also saw it suggested in a forum somewhere and it was adjustable to give me fine tuning ability. no other reason.

I never assembled an upper before either. Its easy. You will need a vice, vice block to hold the barrel when you torque on it, barrel nut wrench and torque wrench. I have all that stuff and if you want to come over when you have the parts I'm about 5 minute drive from your place. We could get the barrel on in about 10 minutes.

For the bipod, your main consideration is how big of magazine are you using. If you have a 40 rounder or something like a surefire 100 round magazine, you need a large bipod to raise the gun up enough to clear the magazine when you are prone.

Stiffer the bipod the better (to get a better bump)

 

[Joe Link]

I did the JARD because I also saw it suggested in a forum somewhere and it was adjustable to give me fine tuning ability. no other reason.

I never assembled an upper before either. Its easy. You will need a vice, vice block to hold the barrel when you torque on it, barrel nut wrench and torque wrench. I have all that stuff and if you want to come over when you have the parts I'm about 5 minute drive from your place. We could get the barrel on in about 10 minutes.

For the bipod, your main consideration is how big of magazine are you using. If you have a 40 rounder or something like a surefire 100 round magazine, you need a large bipod to raise the gun up enough to clear the magazine when you are prone.

Stiffer the bipod the better (to get a better bump)

I appreciate that, and I'll definitely take you up on that if I end up going the DIY route (which is likely).

I think the D60 will fit under a standard 9"-13" bipod, so I should be gtg with a shorter one.

 

[bolus]

I appreciate that, and I'll definitely take you up on that if I end up going the DIY route (which is likely).

I think the D60 will fit under a standard 9"-13" bipod, so I should be gtg with a shorter one.

I just ordered one actually from a black friday sale. I'll measure when it comes in.

I have this barrel. Tactical ammo is in St Helens (about a 40 minute drive from you). They finish them from Columbia river arms which is right next door to them. (neither building has any outside identification that they sell this stuff, but you can jsut drop in and buy one ) They add the coating and threads. I got the low profile gas block and gas tube from them as well.

18" Special Purpose Rifle, 1/2x28 Threads, Black finish

 

[jbett98]

It's been my experience with full auto firearms is that the novelty wears off rather quickly for yourself, but letting other folks enjoy the thrill who otherwise would never get the chance to fire one.

 

[bolus]

It's been my experience with full auto firearms is that the novelty wears off rather quickly for yourself, but letting other folks enjoy the thrill who otherwise would never get the chance to fire one.

plus throwing $10 downrange in 1.2 seconds looses its appeal pretty quickly. You start to want to savor those shots.

 

[Joe Link]

I just ordered one actually from a black friday sale. I'll measure when it comes in.

I have this barrel. Tactical ammo is in St Helens (about a 40 minute drive from you). They finish them from Columbia river arms which is right next door to them. (neither building has any outside identification that they sell this stuff, but you can jsut drop in and buy one ) They add the coating and threads. I got the low profile gas block and gas tube from them as well.

18" Special Purpose Rifle, 1/2x28 Threads, Black finish

Good to know, thanks for the tip.

It's been my experience with full auto firearms is that the novelty wears off rather quickly for yourself, but letting other folks enjoy the thrill who otherwise would never get the chance to fire one.

I'd be lying if I said I wasn't building this for others

 

[jbett98]

The upshot of building one of these poor mans machine gun is that you generally have only spent around $750.00 to upgrade an existing AR to perform like one.
The one thing I didn't anticipate when I inherited my two machine guns was the constant worry about their safekeeping, whether locked up at home or worst yet, just traveling to and from the place where you're shooting them.
It's one thing to have your $1,200.00 AR stolen, it's another when your $20,000.00 not to be replaced in my lifetime Thompson grows legs and jumps into some dirt bags hands.

 

[Joe Link]

I just missed this $400 PSA deal. Would have been the perfect upper

PSA 18" CHF Heavy Barrel Rifle Length 15" Precision Lightweight M-Lok Upper - NO BCG/CH - 516444448

Screenshot since they take these down after the sale.

 

[Joe Link]

I just pulled the trigger on a Slidefire SSAR-15, the KE Arms trigger is here, and my NWFA lowers should be arriving shortly

 

[bolus]

I just missed this $400 PSA deal. Would have been the perfect upper

PSA 18" CHF Heavy Barrel Rifle Length 15" Precision Lightweight M-Lok Upper - NO BCG/CH - 516444448

Screenshot since they take these down after the sale.

View attachment 327672

Here is a 16" with a bull barrel, complete upper and BCG for $359. No idea who Givati is though.
Ar 15 16 Upper receiver assembly 556x45-223 bull barrel -Givati Company USA