Fun with numbers, an unscientific look at spring spaceing

[mikeiniowa]

I had one of the fellows as about using the Merlin XL spring from James Maccarri in the B-26, all I have left on hand today is the .22 so that's what I used. This is a new rifle and the seal, barrel etc is raw so with a run in rifle the numbers can come out different than what I have here.  Starting out with the stock spring and no spacers the velocity with Gamo Hunters (GH) was 645, with RWS Hobby (RWSH) it was 704, I added a top hat that spaced the spring .185 inches, GH-660, RWSH- 736. With the Merlin spring and no spacers GH-627, RWSH-705, with a .185 spacer GH-640, RWSH-720, as I could add more to the Merlin spring I added a .115 delrin washer to the .185 steel top hat, little or no weight added  for GH-645, RWSH-735, so I'm back to were the stock spring was to begin with, with an all steel top hat spaced to .300 the velocity should be higher than the stock spring with no spacing, there is more room to add spacers with the Merlin spring so it could possibly equal the stock spring with the .185 spacer. The one benefit of the Merlin is it reduces the effort needed to cock the rifle, holding just the action in my hands and cocking it with the stock spring is hard, with the Merlin it's a snap. In the stock it's even easier. Had a long day today otherwise I would have turned a few more top hats and taken the Merlin to the limit, my get up and go got up and went....

[shawn67]

Thanks for posting the results Mike, since it makes it easier to cock and shoot smoother and doesn't take away from the velocity, it sounds like something I would like for you to do to mine while you have it there, thanks again for posting the results. I hope I didn't get you to over do it today by asking you about the Merlin.

[Gene_SC]

Great take on the differences of the stock spring and the Merlin spring Mike. I have personally done the same thing on my air rifles to see the differences that springs, metal and delrin tops and washers, etc. would make. Only trade off I could see as you did is the cocking effort.

And I know what you mean at the day's end when the get up got up and left me..

[tjk]

Thanks for the info and tips Mike. Makes me think of the Marksman Bob and I redid. It's a short stroker, very smooth and easy to cock, but the power and velocity is right in line with where I had hoped for,...even more so (last reading with GH's hit the 700 fps plateau)!! The Marksman I bought from Wes that you tuned  is the same. Not as fast, but the trigger is great, and a blast to shoot in-doors! Especially when it's cold out,...like now, it's about 20 degrees here in Dixie,......way too cold for me!!! Burrrrrrr, tjk

[shawn67]

Unforetunately my rifle that I got from Mike didn't perform as well as the one above with the Merlin spring it would barely break 600 with the gamo hunters with the Merlin in it no matter how he spaced it or what he tried, so he put the stock spring back in it and added a tophat then it got the numbers back up to around 670 with the hunters. And I really can't imagine my rifle being any smoother than it is now, its not much different than shooting a regular firearm,  except its quiter and has a little bit different recoil, its more like a steady push isntead of a sharp kick. I absolutely love it. If it was anymore enjoyable the funpolice would make it illegal. I was curious though if a full power tune kit for a R9 from Maccari would work in a B26 since its supposed to be cloned from it, I know if you look up "another airgun blog" on google a guy named Derrick put a spring and spring guide from a R10 in a B26 and a few other neat modifications tha improved the performance of his gun. The guy that did it explains everything he did in detail, I have talked with him, and he didn't know if the Maccari kit would work but he said the stock R10 and guide fit perfect in his but the tolorances on a lot of B26s vary from run to run so it might not work without being modified or even at all in another B26, which probably explains why the Merlin spring didn't work as well in my gun as it did in the other one Mike did. That's why these guys that tune these guns deserve all the praise they get, how they can take a  gun with questionable quality control and turn them into the smooth shooting guns they do is beyond me, its takes a lot of talent to do something like that. I don't have the patients for it, I'd pull my hair out or be in the local funny farm taking courses in basket weaving and valium if I had to try to do what these guys do.

[mikeiniowa]

If the piston has the .770 ID then the R-9 stuff could possibly fit, had a .177 in the shop and the ID measured .740, must have had trouble getting the one size tube for the pistons and substituted the smaller for some rifles in  the run...JM does have some of the B-26 springs in stock but you must measure the ID of the piston before contacting him to make sure it will fit....

[shawn67]

All I know is you made mine awful smooth Mike, if it ever wears out I'll send it back to you and we can try a different one but this one shoots to nice to mess with. Sorry It was such a pain in the butt to get lined out but the end result is great.