My current strategy to tune a RAW HM1000x.LRT (.30 caliber) to shoot various slugs and pellets has become somewhat of a chore. Out of the box the RAW comes tuned from the factory to shoot a specific pellet which it does very well. Tuning for other types of projectiles due to the lack of an externally adjustable regulator is inconvenient at best.
The goal is to find what regulator pressure and hammer spring tension will deliver the best precision at what velocity for each type of projectile. The OEM regulator requires you to remove the air bottle AND regulator from the action block to adjust. An option which I have done is to purchase a HUMA adjustable regulator, however, this still requires the removal of the air bottle to make the adjustment saving the need to remove it from the action body. Still having to remove the air bottle for each change wastes air and takes time and I don’t have patience in abundance.
Initially I was going to simply open either regulator to a very high pressure (say 190 bar) and provide lower pressure to the RAW air bottle from a dual regulated air gauge connected to an large external air tank. This way I can start at a lower pressure, say 140 BAR and work my way up trying various hammer spring settings. However, this does not allow a convenient way to go back and test settings at lower regulator pressures without removing the air bottle and bleeding off air pressure. Again, inconvenient and wasting air.
The solution, bypass the air bottle (remove it) and connect the external dual regulator and air supply directly to the action/barrel with additional fittings from HUMA which I purchased (see red dot 1). However, without the air bottle what would hold the gun in the front rest? I certainly don’t want to rest the barrel on the front rest.
A second concern I have is confirming what the actual air pressure is in the action/plenum and how close it relates to the indicated pressure from the external dual air regulator connected to an external tank. The installation of a digital air gauge into the action is my current solution, however, this requires the action to be tested out of an unaltered stock. This setup will allow me to note the indicated air pressures in the action/plenum that produced the best precision and at what velocity so that I can duplicate that performance when adjusting the HUMA regulator to deliver the same velocity with each projectile I’m likely to use with the digital air gauge in the action removed and the action back in the stock.
So testing the rifle out of the stock poses a challenge which along with no air bottle for support will require a method to secure the rifle in a rest. I looked into purchasing a second hand stock which I would cut off just before the digital air gauge inserted into the action. Used stocks were found in the $275 and up range, so currently that is not an option.
I’m currently working on a bid with a fabricator to make me a jig to hold the action/barrel that I can then hold in my Ransom front and rear rifle rests. Aiming the rifle is anticipated to be done using a TriggerCam camera and smart phone. Maintaining a vertical optic position will be handled by an MDT digital level mounted to the Spuhr scope mount. If I’m able to get behind the optic I may drop the use of the TriggerCam.
My rough sketch of the jig is not to scale and I don’t have any CAD software for my current Windows operating system. I have an very old version of AutoCad, but the upgrade price is not an option at this time.
My next PCP is going to have external regulators and an easier method of tuning. Believe it or not, I still like my RAW, but I’m likely to settle on one or two projectiles once found.
The goal is to find what regulator pressure and hammer spring tension will deliver the best precision at what velocity for each type of projectile. The OEM regulator requires you to remove the air bottle AND regulator from the action block to adjust. An option which I have done is to purchase a HUMA adjustable regulator, however, this still requires the removal of the air bottle to make the adjustment saving the need to remove it from the action body. Still having to remove the air bottle for each change wastes air and takes time and I don’t have patience in abundance.
Initially I was going to simply open either regulator to a very high pressure (say 190 bar) and provide lower pressure to the RAW air bottle from a dual regulated air gauge connected to an large external air tank. This way I can start at a lower pressure, say 140 BAR and work my way up trying various hammer spring settings. However, this does not allow a convenient way to go back and test settings at lower regulator pressures without removing the air bottle and bleeding off air pressure. Again, inconvenient and wasting air.
The solution, bypass the air bottle (remove it) and connect the external dual regulator and air supply directly to the action/barrel with additional fittings from HUMA which I purchased (see red dot 1). However, without the air bottle what would hold the gun in the front rest? I certainly don’t want to rest the barrel on the front rest.
A second concern I have is confirming what the actual air pressure is in the action/plenum and how close it relates to the indicated pressure from the external dual air regulator connected to an external tank. The installation of a digital air gauge into the action is my current solution, however, this requires the action to be tested out of an unaltered stock. This setup will allow me to note the indicated air pressures in the action/plenum that produced the best precision and at what velocity so that I can duplicate that performance when adjusting the HUMA regulator to deliver the same velocity with each projectile I’m likely to use with the digital air gauge in the action removed and the action back in the stock.
So testing the rifle out of the stock poses a challenge which along with no air bottle for support will require a method to secure the rifle in a rest. I looked into purchasing a second hand stock which I would cut off just before the digital air gauge inserted into the action. Used stocks were found in the $275 and up range, so currently that is not an option.
I’m currently working on a bid with a fabricator to make me a jig to hold the action/barrel that I can then hold in my Ransom front and rear rifle rests. Aiming the rifle is anticipated to be done using a TriggerCam camera and smart phone. Maintaining a vertical optic position will be handled by an MDT digital level mounted to the Spuhr scope mount. If I’m able to get behind the optic I may drop the use of the TriggerCam.
My rough sketch of the jig is not to scale and I don’t have any CAD software for my current Windows operating system. I have an very old version of AutoCad, but the upgrade price is not an option at this time.
My next PCP is going to have external regulators and an easier method of tuning. Believe it or not, I still like my RAW, but I’m likely to settle on one or two projectiles once found.
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, it will be obvious right away on the diameter it will like, then fine tune with the speed.
. I found a polished barrel helps, and having a non choked barrel helps, mine is a LW non choked poly. I have found that diameter is the most important aspect for spin stabilization, then twist rate and then speed. When there is no wind while pesting for starlings or ground squirrels, pellets are perfect even at long distance (110yd ground squirrel taken with 18gr) but, when there is wimd, slugs cut thru the wind and POI shift is not nearly as much. I do think slugs have their place with PCP's especially when conditions dictate. They definitely take much more care when shooting than pellets, pellets to me are so much more forgiving as far as a proper sight picture, slugs, if I am off with my sight pic just a smidge, POI will be off, but, if I am on my game, accuracy is the same as pellets (I work on this daily). Slugs are A LOT of work, but worth it in my humble opinion...ask Spiralgroove!