sarpau Posted January 27, 2015 Share Posted January 27, 2015 That was my understanding as well, By the same logic (I think), the lighter the gun, the easier it can move under recoil, thus compressing the inertia spring against the bolt which stays in place until the spring decompresses and cycles the action. Link to comment Share on other sites More sharing options...
louu Posted January 27, 2015 Share Posted January 27, 2015 Hey Mr. Kelley any idea why they went with a 24" barrel on the new 3 gun version instead of the 26"??? I'm no Mr. Kelley but doesn't everyone want a 21" barrel on 3-gun or tactical shotgun? That used to be the norm. 24" is the shortest they have built thus far. When in the Stoeger booth at shot shot I had about the same number ask for a 21 as a 26". Yeah that makes sense, its gotta be tacticool for the mall ninjas. Link to comment Share on other sites More sharing options...
kurtm Posted January 27, 2015 Share Posted January 27, 2015 (edited) Sarpau, I can't speak to the Stoger shotguns, but I can talk about Benelli. Yes you can get M2 performance in the SBE for the most part. BTW the inertia springs are the same in both! Yes the main springs are different! How the internals interact AFTER the gun unlocks is critical to reliability. Internal ballistic plays a HUGE part in how well it will all work together. You say you want to play? Well here ya go. You will need at least 4 spare inertia springs, a spare extractor, possibly a spare barrel extension, and some tungsten carbide reamers. There are several ways to "weaken" a spring. Make it shorter, make it smaller buy grinding off some of the wire diameter, collapse it to coil stack violently, or annealing part of the coil stack. You could just call up a spring maker, send them a sample spring and say I want one just like this only X% lighter.....which of course is just going to be a W.A.G. because you really don't know the cycle speed window of what works this system. Now get to whacking, grinding, heating, and as you will find out quickly, reaming the inside coil diameter of your inertia springs to change their weight. Try each rendition a bunch. Now you have a path to your playground. Enjoy your winter. Edited January 27, 2015 by kurtm Link to comment Share on other sites More sharing options...
MarkCO Posted January 27, 2015 Share Posted January 27, 2015 Isn't that contrary to how the inertia system works? Doesn't adding more weight to the gun decrease reliability with lighter loads? Your tube is a one piece steel tube with an added sleeve over top correct? Just when you thought you kind of understood the working of the system... We are adding a little weight, but less than just adding an extension and clamp. The increased reliability with the lighter loads comes from the significant reduction of drag on the stainless steel tube we use. It is also a tighter fit in the barrel hanger which tightens up the connection, and thus slug accuracy. Link to comment Share on other sites More sharing options...
kurtm Posted January 27, 2015 Share Posted January 27, 2015 Oh thats just crazy Mark! You mean you are changing how the internal parts interact (less friction, less flex) after the gun unlocks! How can that help anything?....just plain crazy I tell ya!!! Link to comment Share on other sites More sharing options...
MarkCO Posted January 27, 2015 Share Posted January 27, 2015 JP did it for rifles, a little technology transfer. Link to comment Share on other sites More sharing options...
sarpau Posted January 27, 2015 Share Posted January 27, 2015 Thanks for the info Kurt/Mark. Inertia springs are relatively cheap so I'll see if I can find a few and mess around a bit for schits and giggles. Not looking for a "game changer" or anything... Link to comment Share on other sites More sharing options...
MarkCO Posted January 27, 2015 Share Posted January 27, 2015 If you went to shot show, there were so many things branded as "game changers" that if they were accurate, we would not even recognize the game anymore. Enjoy the experimentation. Link to comment Share on other sites More sharing options...
P.E. Kelley Posted January 27, 2015 Share Posted January 27, 2015 Thanks for the info Kurt/Mark. Inertia springs are relatively cheap so I'll see if I can find a few and mess around a bit for schits and giggles. Not looking for a "game changer" or anything... Please press on with your experiment...but I believe Kurt inferred it has all been done before. I know I have and it is a blind hole as far as any performance gain. But your trip (as others before you) will be enlightening. Link to comment Share on other sites More sharing options...
sarpau Posted January 27, 2015 Share Posted January 27, 2015 (edited) I fully agree, and most of my "advancement" in my hobbies (and pretty much anything in my life) is though learning from other's experiences. Someone already did the legwork. No need to reinvent the wheel. Once and a while though, you have to play a bit on your own. Keeps things interesting. I'm having visions of light inertia springs and a shot filled bolt carrier to act as a deadblow and prevent bolt bounce... Or would that amplify the bounce??? LOL. Edited January 27, 2015 by sarpau Link to comment Share on other sites More sharing options...
kurtm Posted January 27, 2015 Share Posted January 27, 2015 (edited) Please take note that you very well might need a new barrel extension...or with Stoger maybe a whole new barrel, I don't know if the extension can be replaced like on Benelli. You will more than likely need a new bolt carrier tail. Possibly a bolt carrier as I really don't know about the Stoger heat treating, and an extractor. Those are the cheap parts you more than likely will break. Pay close attention to where the bolt carrier hits the back of the receiver as well. It is kind of cool to note that most inertia guns will run for a short while with only one locking lug recess fairly reliably, you just need heavier shells. It is also neat when both locking lug recesses fail and you have an "inertia direct blow back" shotgun. Fun and exciting! It will give you a look on your face like someone jumped on your enema bag .... and a reason to buy yet another quality $350.00 dollar shotgun! You will have a game changer alright......you just really don't know the game your playing!!! Edited January 27, 2015 by kurtm Link to comment Share on other sites More sharing options...
MarkCO Posted January 27, 2015 Share Posted January 27, 2015 Fun and exciting! It will give you a look on your face like someone jumped on your enema bag Good thing I only am using this keyboard for another 3 days, I just spit my lunch all over it. Link to comment Share on other sites More sharing options...
kurtm Posted January 27, 2015 Share Posted January 27, 2015 Ooops!!! Darn!!! Forgot to tell you to lay in at least twice the amount of cam pins as you have inertia springs. The dead blow idea is great.....but it makes bolt bounce terrible.....unless you shorten the inertia spring a bunch...which will.....oh you'll see. Have fun, and ALWAYS wear eye protection and always shoot it off the right shoulder... stuff usually comes out the ejection port side, and none of this stuff is a guess! Link to comment Share on other sites More sharing options...
sarpau Posted January 27, 2015 Share Posted January 27, 2015 Awesome!! Thanks Kurt. Wish I lived closer. Would love to pick your brain over a few drinks. Anyway, enough thread derailing. Stoeger M3000. Awesome entry level platform and great to see so much support for it!! Link to comment Share on other sites More sharing options...
Jesse Tischauser Posted January 27, 2015 Share Posted January 27, 2015 Isn't that contrary to how the inertia system works? Doesn't adding more weight to the gun decrease reliability with lighter loads? Your tube is a one piece steel tube with an added sleeve over top correct? Just when you thought you kind of understood the working of the system... We are adding a little weight, but less than just adding an extension and clamp. The increased reliability with the lighter loads comes from the significant reduction of drag on the stainless steel tube we use. It is also a tighter fit in the barrel hanger which tightens up the connection, and thus slug accuracy. That's what I figured you'd say. Makes lots of sense. My 5 year old M2 is considerably smoother than any of my M3K's. Link to comment Share on other sites More sharing options...
Jesse Tischauser Posted January 27, 2015 Share Posted January 27, 2015 Hey Mr. Kelley any idea why they went with a 24" barrel on the new 3 gun version instead of the 26"???I'm no Mr. Kelley but doesn't everyone want a 21" barrel on 3-gun or tactical shotgun? That used to be the norm. 24" is the shortest they have built thus far. When in the Stoeger booth at shot shot I had about the same number ask for a 21 as a 26". Yeah that makes sense, its gotta be tacticool for the mall ninjas. Unfortunately They out number 3-gunners 3:1 or more. Link to comment Share on other sites More sharing options...
MarkCO Posted January 27, 2015 Share Posted January 27, 2015 Ooops!!! Darn!!! Forgot to tell you to lay in at least twice the amount of cam pins as you have inertia springs. The dead blow idea is great.....but it makes bolt bounce terrible.....unless you shorten the inertia spring a bunch...which will.....oh you'll see. Have fun, and ALWAYS wear eye protection and always shoot it off the right shoulder... stuff usually comes out the ejection port side, and none of this stuff is a guess! KurtM, the warning label for Inertia Driven operating system tinkering. Link to comment Share on other sites More sharing options...
Vlad Posted January 27, 2015 Share Posted January 27, 2015 Kurt should write a book, "Tales of Redneck Tinkering and Ballistic Rumpus". Link to comment Share on other sites More sharing options...
Jim Norman Posted January 27, 2015 Share Posted January 27, 2015 Maybe I am just lucky, but my M3K runs Wally World Winchester 1-1/8 3 dram loads, # 7.5 or #8 at 1200fps. I have had just a couple chugs with Fiocchi low recoil slugs. Not lucky. That is the proper load for the gun! (within the context of our game) OK, not luck, just using the right stuff and not screwing with success. I'll take it! Usually I figure out somewhat to get it all working and then take one step to far! Link to comment Share on other sites More sharing options...
openclassterror Posted January 27, 2015 Share Posted January 27, 2015 (edited) We have learned some interesting things while experimenting with our inertia-operated AR-based shotgun over the last 6 months. In effect, it is the reciprocating system of a Benelli M2 fit into a large platform AR. Here are a few notes- With carrier assembly weight matched to the M2 within 3 grams, and factory M2 recoil spring preloaded to same length as M2, and off-the-shelf M2 Bolt head, inertia spring, firing pin spring, firing pin, and recoil spring, it was reliable with 1-1/8@1200 loads. However- Decrease carrier mass by 10%- NO LOVE Increase preload on recoil spring by 1/2"- NO LOVE Remove 6 coils from recoil spring- NO LOVE Increase bolt stroke by 3/8"- NO LOVE Add friction of shell against bottom of bolt while cycling- NO LOVE The inertia system design is very carefully balanced. If you change ANY parameter, it has an effect on one or more other parameters. The force between the inertia spring and recoil spring MUST maintain a bias within a very narrow window, since they act on the carrier in opposite directions. Since there are very few spring choices available similar to the hugely powerful inertia spring, we treated it as a constant. Manipulating the carrier weight required a modification of the recoil spring, since the reduced weight carrier has less mass. Reducing the recoil spring tension lessens the bolt's ability to close on a tight or dirty shell. After tweaking the design every which way from Sunday, we eventually ended up back where we started- With specs an awful lot like the M2. BTW, the total reciprocating assembly (including the rails up to the spring)on the M3000 is within 5 grams of the M2 recip assembly. The 3500 uses the SAME carrier, bolt, and inertia spring as the 3000, but the recoil spring and rail assembly are 5/8" longer, as is the bolt stroke. Food for thought. Edited January 27, 2015 by openclassterror Link to comment Share on other sites More sharing options...
Jesse Tischauser Posted January 28, 2015 Share Posted January 28, 2015 We have learned some interesting things while experimenting with our inertia-operated AR-based shotgun over the last 6 months. In effect, it is the reciprocating system of a Benelli M2 fit into a large platform AR. Here are a few notes- With carrier assembly weight matched to the M2 within 3 grams, and factory M2 recoil spring preloaded to same length as M2, and off-the-shelf M2 Bolt head, inertia spring, firing pin spring, firing pin, and recoil spring, it was reliable with 1-1/8@1200 loads. However- Decrease carrier mass by 10%- NO LOVE Increase preload on recoil spring by 1/2"- NO LOVE Remove 6 coils from recoil spring- NO LOVE Increase bolt stroke by 3/8"- NO LOVE Add friction of shell against bottom of bolt while cycling- NO LOVE The inertia system design is very carefully balanced. If you change ANY parameter, it has an effect on one or more other parameters. The force between the inertia spring and recoil spring MUST maintain a bias within a very narrow window, since they act on the carrier in opposite directions. Since there are very few spring choices available similar to the hugely powerful inertia spring, we treated it as a constant. Manipulating the carrier weight required a modification of the recoil spring, since the reduced weight carrier has less mass. Reducing the recoil spring tension lessens the bolt's ability to close on a tight or dirty shell. After tweaking the design every which way from Sunday, we eventually ended up back where we started- With specs an awful lot like the M2. BTW, the total reciprocating assembly (including the rails up to the spring)on the M3000 is within 5 grams of the M2 recip assembly. The 3500 uses the SAME carrier, bolt, and inertia spring as the 3000, but the recoil spring and rail assembly are 5/8" longer, as is the bolt stroke. Food for thought. Great info Tom! Link to comment Share on other sites More sharing options...
kurtm Posted January 28, 2015 Share Posted January 28, 2015 I would venture that your brand new M2 is far smoother than any of your M3000,s Jesse. Link to comment Share on other sites More sharing options...
kurtm Posted January 28, 2015 Share Posted January 28, 2015 (edited) Doubled Edited January 28, 2015 by kurtm Link to comment Share on other sites More sharing options...
BOOM Posted January 28, 2015 Share Posted January 28, 2015 Thanks Tom; good info on what did nothing to improve the reliability of the MK3. I'd like to change out the extractor, and extractor spring to the M2 parts. Only because its cheep insurance. Link to comment Share on other sites More sharing options...
Jesse Tischauser Posted January 28, 2015 Share Posted January 28, 2015 I would venture that your brand new M2 is far smoother than any of your M3000,s Jesse. You are correct again. I hope I have made it abundantly clear that the M3k is not a replacement for a Benelli M2 or even an M1. It is an great $500 gun with the reliable inertia driven system. The price point and features are a perfect combo for the entry level market. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now