An ultra-budget pump pistol/gun often sold as a ready-to-play kit, the cheapest way to try pump-action play.
Technical Specifications
Operation
Pump pistol (blowforward)
Firing Modes
pump
Caliber
.68
Feed System
Internal/12g feed
Air Source
12g CO2
Operating Pressure
~400 psi
Weight (unloaded)
1.4 lbs
MSRP
$50
Street Price
$40-80
Maintenance
Low
Notable features: 12-gram powered, Ready-to-play kit, Very compact
Pros & Cons
Pros
Cheapest pump option
Self-contained 12g
Fun novelty
Cons
Very low capacity
Toy-grade build
Best for: Backyard/casual, Kids/family, Pump novelty
Setup & First-Day Tuning Guide
Inspect the Pump Stroke — Before adding air, pull the pump handle back fully then push forward. On the JT ER2 Pump RTP it should move smoothly — any roughness means the pump rod needs a coat of Dow 33 grease.
Check the Ball Detent — Inspect the ball detent that holds rounds in the breech. A worn detent is the #1 cause of ball drops in pump guns. It should offer clear resistance when pressed.
Dry-Cycle Before Air — With no air and no balls, pump-cycle 10 times to feel the trigger break. Commit to a full pump stroke every rep — short-stroking is the most common first-day jam and it's technique, not the gun.
Connect Air & Check Fittings — Thread on your HPA or CO2 tank slowly and listen at all connections for any hissing. The JT ER2 Pump RTP runs well on either source — HPA gives more consistent velocity.
Chronograph to Your Field Limit — Fire 5 shots across the chronograph. Adjust the velocity screw inside the grip frame — clockwise raises, counter-clockwise lowers. Target 280 fps (confirm your field's limit). Pump guns typically run ±3–5 fps.
Load & Practice Full Pump Strokes — Load a 10-round tube and fire at a safe backstop. A confident, complete pump stroke eliminates 90% of field jams.
Maintenance Schedule
Interval
Task
Detail
After every outing
Barrel, bolt & exterior clean
Squeegee twice, bolt wipe, screws snug.
Every 5 sessions
Bolt O-ring lube & cup seal check
Clean with isopropyl, dry, apply Dow 33. Inspect cup seal — replace if deformed.
Every 6 months
Valve & fitting service
Re-lube all O-rings. Check all fittings and inline regulator if present.
Annually
Full teardown & O-ring replacement
Complete disassembly, full O-ring kit replacement, inspect springs.
Minimal maintenance; replace 12g, lube o-rings.
Common Problems & Troubleshooting
Pump drags or binds
Cause: Dry pump rod; over-tightened arm bolts
Fix: Apply Dow 33 to the pump rod and inside the pump arm guide. Check arm bolts are snug but not overtorqued.
Ball drops from breech
Cause: Worn ball detent
Fix: Check the ball detent on the JT ER2 Pump RTP — replace if it offers no resistance. Detents cost under $5.
Gun won't cock
Cause: Worn pump-arm catch; broken spring
Fix: Inspect the catch pawl and pump return spring. Replace the spring if broken — available from the manufacturer.
Velocity drops suddenly
Cause: Cup seal failure; low tank pressure
Fix: Check tank pressure, then inspect the cup seal — replace if flat or cracked. Full O-ring kit is under $10.
Upgrade Path
12g CO2
Mostly used as-is
Frequently Asked Questions
Is the JT ER2 Pump RTP good for beginners?
Yes — the JT ER2 Pump RTP is an excellent first-time gun. It's durable and forgiving of beginner mistakes.
Does the JT ER2 Pump RTP run on CO2 or HPA?
Compatible with 12g CO2. CO2 works but HPA gives significantly more consistent velocity and is better for long-term seal health.
What is the operating pressure of the JT ER2 Pump RTP?
The JT ER2 Pump RTP operates at ~400 psi. Match your regulator output to this spec.
How hard is the JT ER2 Pump RTP to maintain?
Easy — basic bolt cleaning every few sessions. Minimal maintenance; replace 12g, lube o-rings.
What loader does the JT ER2 Pump RTP need?
Pump guns use tubes or pods — no electronic loader needed.
How much does the JT ER2 Pump RTP cost?
New: $50 MSRP, typically $40-80 on the street. Used prices vary — check BST forums and eBay for current asking prices.
What barrel thread does the JT ER2 Pump RTP use?
The JT ER2 Pump RTP shoots .68 caliber. Confirm the specific thread pattern for your variant before ordering a barrel.
What firing modes does the JT ER2 Pump RTP support?
Supported modes: pump. Most recreational fields require semi-auto only.
How heavy is the JT ER2 Pump RTP?
1.4 lbs unloaded. With a full hopper and HPA tank, expect roughly 3.9–4.9 lbs total.
Is the JT ER2 Pump RTP worth buying?
An ultra-budget pump pistol/gun often sold as a ready-to-play kit, the cheapest way to try pump-action play. Strengths: Cheapest pump option, Self-contained 12g. Trade-offs: Very low capacity, Toy-grade build.