sleeving versus stroking....

[greenwayjames]

ive noticed of late 2 trends .. firstly the ever de-creasing bore size [sleeving down to 23mm now from nick]
and ive also spotted daves work from stroking a [i think] 30mm chamber to something around 45mm
and that got me wondering which is best ?
my innitial thoughts are thus........
a narrow bore and medium stroke should give better flow to [and through] the transfer port....... all the pressure and turbulence is directed from a much narrower band toward the port, this maybe great for efficiency ? !

but....... on the other hand, a 40 something mm stroke [despite having a larger bore] should give a rediculously fast lock time...... reducing hold sensitivity hugely ?
so i guess the question is, which direction is favourable in terms of muzzle flip/recoil reduction ?

As I was saying before the interruption - the 7/8" bore experimental rifle that I shot was a total joy. Definitely the right way to go for UK limits so why bother making another rifle with an enormous bore, I asked. The answer was to make the powerplant more compact especially if a piston wall trigger system was used rather than a piston rod with trigger mechanism in line. The other area JB wanted to look at was that of power for export markets where, if the cost could be in the right ballpark, the largest market for the product lay. I will ask if the bigbore powerplant is still about and if I can have a try. I will report the results if allowed. BTW JB said he still had a considerable quantity of 7/8" bore x 1/16 wall good quality seamless tubing if anyone wanted to have a go at sleeving but only required a short length. If only a few inches, for a sleeve, were needed he only wanted postage costs.

[Shed tuner]

BTW JB said he still had a considerable quantity of 7/8" bore x 1/16 wall good quality seamless tubing if anyone wanted to have a go at sleeving but only required a short length. If only a few inches, for a sleeve, were needed he only wanted postage costs.

I'd like a couple of short lengths please... around 4.5" long should be enough - all I've found so far is 23mm ID 26mm OD, which is a bit tedious to turn down (just spent 30 mins doing it in fact !) please PM us your details for payment / postage / £££ etc ta - JB

Also tks for the other info, pity it never "made it"...

(goes back to the garage to finish off his own 23mm experiment; tube done, piston done, just the o-ring nose to finish and the comp tube trans port do do now - maybe today I should have something )

[greenwayjames]

I'd like a couple of short lengths please... around 4.5" long should be enough - all I've found so far is 23mm ID 26mm OD, which is a bit tedious to turn down (just spent 30 mins doing it in fact !) please PM us your details for payment / postage / £££ etc ta - JB

Also tks for the other info, pity it never "made it"...

(goes back to the garage to finish off his own 23mm experiment; tube done, piston done, just the o-ring nose to finish and the comp tube trans port do do now - maybe today I should have something )

You woud have to contact JB direct and ask him for the tubing. 0121 745 4287. I dont wish to get involved but just extended his offer to any bodgers here

[NickG]

Bodgers,? That's a bit derogatory, are you some sort of expert then, I assume you have engineering credentials ?

[greenwayjames]

Bodgers,? That's a bit derogatory, are you some sort of expert then, I assume you have engineering credentials ?

After bodgers i used the . Dont be so grumpy.

And no I dont have any credentials, especially in the cold weather